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Texas Instruments TMS320DM335 DMSoC Universal Serial Bus (USB) User guides
TMS320DM335
Digital Media System-on-Chip (DMSoC)
Universal Serial Bus (USB)
Reference Guide
Literature Number: SPRUFY9
July 2008
2
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Contents
Preface....................................................................................................................................... 11
1
Introduction ....................................................................................................................... 14
1.1
2
3
4
Purpose of the Peripheral .............................................................................................. 14
.................................................................................................................. 14
1.3
Functional Block Diagram .............................................................................................. 15
1.4
Supported Use Case Examples ....................................................................................... 16
1.5
Industry Standard(s) Compliance Statement ........................................................................ 22
Peripheral Architecture ....................................................................................................... 23
2.1
Clock Control ............................................................................................................. 23
2.2
Signal Descriptions ...................................................................................................... 23
2.3
USB_DP / USB_DM Polarity Inversion ............................................................................... 24
2.4
Indexed and Non-Indexed Registers .................................................................................. 24
2.5
USB PHY Initialization .................................................................................................. 24
2.6
VBUS Voltage Sourcing Control ....................................................................................... 24
2.7
Dynamic FIFO Sizing ................................................................................................... 25
USB Controller Host and Peripheral Modes Operation ............................................................ 25
3.1
USB Controller Peripheral Mode Operation .......................................................................... 27
3.2
USB Controller Host Mode Operation ................................................................................ 45
3.3
DMA Operation .......................................................................................................... 58
3.4
Interrupt Handling........................................................................................................ 69
3.5
Test Modes ............................................................................................................... 70
3.6
Reset Considerations ................................................................................................... 72
3.7
Interrupt Support ......................................................................................................... 72
3.8
DMA Event Support ..................................................................................................... 72
3.9
Power Management ..................................................................................................... 72
Registers ........................................................................................................................... 73
4.1
Control Register (CTRLR) .............................................................................................. 80
4.2
Status Register (STATR) ............................................................................................... 80
4.3
RNDIS Register (RNDISR) ............................................................................................. 81
4.4
Auto Request Register (AUTOREQ) .................................................................................. 82
4.5
USB Interrupt Source Register (INTSRCR) .......................................................................... 83
4.6
USB Interrupt Source Set Register (INTSETR) ..................................................................... 84
4.7
USB Interrupt Source Clear Register (INTCLRR) ................................................................... 85
4.8
USB Interrupt Mask Register (INTMSKR) ............................................................................ 86
4.9
USB Interrupt Mask Set Register (INTMSKSETR) .................................................................. 87
4.10 USB Interrupt Mask Clear Register (INTMSKCLRR) ............................................................... 88
4.11 USB Interrupt Source Masked Register (INTMASKEDR) .......................................................... 89
4.12 USB End of Interrupt Register (EOIR) ................................................................................ 90
4.13 USB Interrupt Vector Register (INTVECTR) ......................................................................... 90
4.14 Transmit CPPI Control Register (TCPPICR) ......................................................................... 91
4.15 Transmit CPPI Teardown Register (TCPPITDR) .................................................................... 91
1.2
Features
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4.16
Transmit CPPI DMA Controller End of Interrupt Register (TCPPIEOIR) ......................................... 92
4.17
Transmit CPPI DMA Controller Interrupt Vector Register (TCPPIIVECTR)
4.18
4.19
4.20
4.21
4.22
4.23
4.24
4.25
4.26
4.27
4.28
4.29
4.30
4.31
4.32
4.33
4.34
4.35
4.36
4.37
4.38
4.39
4.40
4.41
4.42
4.43
4.44
4.45
4.46
4.47
4.48
4.49
4.50
4.51
4.52
4.53
4.54
4.55
4.56
4.57
4.58
4.59
4.60
4.61
4.62
4.63
4.64
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..................................... 92
Transmit CPPI Masked Status Register (TCPPIMSKSR) .......................................................... 93
Transmit CPPI Raw Status Register (TCPPIRAWSR) ............................................................. 93
Transmit CPPI Interrupt Enable Set Register (TCPPIIENSETR) ................................................. 94
Transmit CPPI Interrupt Enable Clear Register (TCPPIIENCLRR) ............................................... 94
Receive CPPI Control Register (RCPPICR) ......................................................................... 95
Receive CPPI Masked Status Register (RCPPIMSKSR) .......................................................... 95
Receive CPPI Raw Status Register (RCPPIRAWSR) .............................................................. 96
Receive CPPI Interrupt Enable Set Register (RCPPIENSETR) ................................................... 96
Receive CPPI Interrupt Enable Clear Register (RCPPIIENCLRR) ............................................... 97
Receive Buffer Count 0 Register (RBUFCNT0) ..................................................................... 97
Receive Buffer Count 1 Register (RBUFCNT1) ..................................................................... 98
Receive Buffer Count 2 Register (RBUFCNT2) ..................................................................... 98
Receive Buffer Count 3 Register (RBUFCNT3) ..................................................................... 99
Transmit CPPI DMA State Word 0 (TCPPIDMASTATEW0) ....................................................... 99
Transmit CPPI DMA State Word 1 (TCPPIDMASTATEW1) ..................................................... 100
Transmit CPPI DMA State Word 2 (TCPPIDMASTATEW2) ..................................................... 101
Transmit CPPI DMA State Word 3 (TCPPIDMASTATEW3) ..................................................... 101
Transmit CPPI DMA State Word 4 (TCPPIDMASTATEW4) ..................................................... 102
Transmit CPPI DMA State Word 5 (TCPPIDMASTATEW5) ..................................................... 103
Transmit CPPI Completion Pointer (TCPPICOMPPTR) .......................................................... 104
Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0) ...................................................... 105
Receive CPPI DMA State Word 1 (RCPPIDMASTATEW1) ...................................................... 105
Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2) ...................................................... 106
Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3) ...................................................... 106
Receive CPPI DMA State Word 4 (RCPPIDMASTATEW4) ...................................................... 107
Receive CPPI DMA State Word 5 (RCPPIDMASTATEW5) ...................................................... 107
Receive CPPI DMA State Word 6 (RCPPIDMASTATEW6) ...................................................... 108
Receive CPPI Completion Pointer (RCPPICOMPPTR)........................................................... 109
Function Address Register (FADDR) ................................................................................ 109
Power Management Register (POWER) ............................................................................ 110
Interrupt Register for Endpoint 0 Plus Transmit Endpoints 1 to 4 (INTRTX) ................................... 111
Interrupt Register for Receive Endpoints 1 to 4 (INTRRX) ....................................................... 111
Interrupt Enable Register for INTRTX (INTRTXE) ................................................................. 112
Interrupt Enable Register for INTRRX (INTRRXE) ................................................................ 112
Interrupt Register for Common USB Interrupts (INTRUSB) ...................................................... 113
Interrupt Enable Register for INTRUSB (INTRUSBE) ............................................................. 114
Frame Number Register (FRAME) .................................................................................. 115
Index Register for Selecting the Endpoint Status and Control Registers (INDEX) ............................ 115
Register to Enable the USB 2.0 Test Modes (TESTMODE) ..................................................... 116
Maximum Packet Size for Peripheral/Host Transmit Endpoint (TXMAXP) ..................................... 117
Control Status Register for Endpoint 0 in Peripheral Mode (PERI_CSR0) ..................................... 118
Control Status Register for Endpoint 0 in Host Mode (HOST_CSR0) ......................................... 119
Control Status Register for Peripheral Transmit Endpoint (PERI_TXCSR) .................................... 120
Control Status Register for Host Transmit Endpoint (HOST_TXCSR) ......................................... 121
Maximum Packet Size for Peripheral Host Receive Endpoint (RXMAXP) ..................................... 122
Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR) ..................................... 123
Control Status Register for Host Receive Endpoint (HOST_RXCSR) ......................................... 124
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4.65
Count 0 Register (COUNT0).......................................................................................... 125
4.66
Receive Count Register (RXCOUNT) ............................................................................... 125
4.67
Type Register (Host mode only) (HOST_TYPE0)
126
4.68
Transmit Type Register (Host mode only) (HOST_TXTYPE)
126
4.69
4.70
4.71
4.72
4.73
4.74
4.75
4.76
4.77
4.78
4.79
4.80
4.81
4.82
4.83
4.84
4.85
4.86
4.87
4.88
4.89
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...................................................
NAKLimit0 Register (Host mode only) (HOST_NAKLIMIT0) ....................................................
Transmit Interval Register (Host mode only) (HOST_TXINTERVAL) ..........................................
Receive Type Register (Host mode only) (HOST_RXTYPE) ...................................................
Receive Interval Register (Host mode only) (HOST_RXINTERVAL) ..........................................
Configuration Data Register (CONFIGDATA) ......................................................................
Transmit and Receive FIFO Register for Endpoint 0 (FIFO0) ...................................................
Transmit and Receive FIFO Register for Endpoint 1 (FIFO1) ...................................................
Transmit and Receive FIFO Register for Endpoint 2 (FIFO2) ...................................................
Transmit and Receive FIFO Register for Endpoint 3 (FIFO3) ...................................................
Transmit and Receive FIFO Register for Endpoint 4 (FIFO4) ...................................................
OTG Device Control Register (DEVCTL) ...........................................................................
Transmit Endpoint FIFO Size (TXFIFOSZ) .........................................................................
Receive Endpoint FIFO Size (RXFIFOSZ) .........................................................................
Transmit Endpoint FIFO Address (TXFIFOADDR) ................................................................
Receive Endpoint FIFO Address (RXFIFOADDR).................................................................
Transmit Function Address (TXFUNCADDR) ......................................................................
Transmit Hub Address (TXHUBADDR) .............................................................................
Transmit Hub Port (TXHUBPORT) ..................................................................................
Receive Function Address (RXFUNCADDR) ......................................................................
Receive Hub Address (RXHUBADDR) ..............................................................................
Receive Hub Port (RXHUBPORT) ...................................................................................
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Contents
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Functional Block Diagram ................................................................................................. 15
Interrupt Service Routine Flow Chart .................................................................................... 26
CPU Actions at Transfer Phases ......................................................................................... 30
Sequence of Transfer ...................................................................................................... 31
Service Endpoint 0 Flow Chart ........................................................................................... 33
IDLE Mode Flow Chart .................................................................................................... 34
TX Mode Flow Chart ....................................................................................................... 35
RX Mode Flow Chart....................................................................................................... 36
Setup Phase of a Control Transaction Flow Chart..................................................................... 46
IN Data Phase Flow Chart ................................................................................................ 48
OUT Data Phase Flow Chart ............................................................................................. 49
Completion of SETUP or OUT Data Phase Flow Chart ............................................................... 50
Completion of IN Data Phase Flow Chart ............................................................................... 52
Tx Queue Flow Chart ...................................................................................................... 61
Rx Queue Flow Chart ...................................................................................................... 66
Control Register (CTRLR) ................................................................................................. 80
Status Register (STATR) .................................................................................................. 80
RNDIS Register (RNDISR)................................................................................................ 81
Auto Request Register (AUTOREQ)..................................................................................... 82
USB Interrupt Source Register (INTSRCR)............................................................................. 83
USB Interrupt Source Set Register (INTSETR) ........................................................................ 84
USB Interrupt Source Clear Register (INTCLRR) ...................................................................... 85
USB Interrupt Mask Register (INTMSKR)............................................................................... 86
USB Interrupt Mask Set Register (INTMSKSETR) .................................................................... 87
USB Interrupt Mask Clear Register (INTMSKCLRR) .................................................................. 88
USB Interrupt Source Masked Register (INTMASKEDR) ............................................................. 89
USB End of Interrupt Register (EOIR) ................................................................................... 90
USB Interrupt Vector Register (INTVECTR) ............................................................................ 90
Transmit CPPI Control Register (TCPPICR) ........................................................................... 91
Transmit CPPI Teardown Register (TCPPITDR) ...................................................................... 91
Transmit CPPI DMA Controller End of Interrupt Register (TCPPIEOIR) ........................................... 92
Transmit CPPI DMA Controller Interrupt Vector Register (TCPPIIVECTR) ........................................ 92
Transmit CPPI Masked Status Register (TCPPIMSKSR) ............................................................ 93
Transmit CPPI Raw Status Register (TCPPIRAWSR) ................................................................ 93
Transmit CPPI Interrupt Enable Set Register (TCPPIIENSETR) .................................................... 94
Transmit CPPI Interrupt Enable Clear Register (TCPPIIENCLRR) .................................................. 94
Receive CPPI Control Register (RCPPICR) ............................................................................ 95
Receive CPPI Masked Status Register (RCPPIMSKSR) ............................................................. 95
Receive CPPI Raw Status Register (RCPPIRAWSR)................................................................. 96
Receive CPPI Interrupt Enable Set Register (RCPPIENSETR) ..................................................... 96
Receive CPPI Interrupt Enable Clear Register (RCPPIIENCLRR) .................................................. 97
Receive Buffer Count 0 Register (RBUFCNT0) ........................................................................ 97
Receive Buffer Count 1 Register (RBUFCNT1) ........................................................................ 98
Receive Buffer Count 2 Register (RBUFCNT2) ........................................................................ 98
Receive Buffer Count 3 Register (RBUFCNT3) ........................................................................ 99
Transmit CPPI DMA State Word 0 (TCPPIDMASTATEW0) ......................................................... 99
Transmit CPPI DMA State Word 1 (TCPPIDMASTATEW1) ........................................................ 100
Transmit CPPI DMA State Word 2 (TCPPIDMASTATEW2) ........................................................ 101
Transmit CPPI DMA State Word 3 (TCPPIDMASTATEW3) ........................................................ 101
Transmit CPPI DMA State Word 4 (TCPPIDMASTATEW4) ........................................................ 102
Transmit CPPI DMA State Word 5 (TCPPIDMASTATEW5) ........................................................ 103
Transmit CPPI Completion Pointer (TCPPICOMPPTR) ............................................................. 104
List of Figures
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Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0) ........................................................
Receive CPPI DMA State Word 1 (RCPPIDMASTATEW1) ........................................................
Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2) ........................................................
Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3) ........................................................
Receive CPPI DMA State Word 4 (RCPPIDMASTATEW4) ........................................................
Receive CPPI DMA State Word 5 (RCPPIDMASTATEW5) ........................................................
Receive CPPI DMA State Word 6 (RCPPIDMASTATEW6) ........................................................
Receive CPPI Completion Pointer (RCPPICOMPPTR) .............................................................
Function Address Register (FADDR) ..................................................................................
Power Management Register (POWER) ..............................................................................
Interrupt Register for Endpoint 0 Plus Tx Endpoints 1 to 4 (INTRTX) .............................................
Interrupt Register for Receive Endpoints 1 to 4 (INTRRX) ..........................................................
Interrupt Enable Register for INTRTX (INTRTXE)....................................................................
Interrupt Enable Register for INTRRX (INTRRXE) ...................................................................
Interrupt Register for Common USB Interrupts (INTRUSB) .........................................................
Interrupt Enable Register for INTRUSB (INTRUSBE) ...............................................................
Frame Number Register (FRAME) .....................................................................................
Index Register for Selecting the Endpoint Status and Control Registers (INDEX) ...............................
Register to Enable the USB 2.0 Test Modes (TESTMODE) ........................................................
Maximum Packet Size for Peripheral/Host Transmit Endpoint (TXMAXP) ........................................
Control Status Register for Endpoint 0 in Peripheral Mode (PERI_CSR0) .......................................
Control Status Register for Endpoint 0 in Host Mode (HOST_CSR0) .............................................
Control Status Register for Peripheral Transmit Endpoint (PERI_TXCSR) .......................................
Control Status Register for Host Transmit Endpoint (HOST_TXCSR) ............................................
Maximum Packet Size for Peripheral Host Receive Endpoint (RXMAXP) ........................................
Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR) .......................................
Control Status Register for Host Receive Endpoint (HOST_RXCSR) .............................................
Count 0 Register (COUNT0) ............................................................................................
Receive Count Register (RXCOUNT) ..................................................................................
Type Register (Host mode only) (HOST_TYPE0) ....................................................................
Transmit Type Register (Host mode only) (HOST_TXTYPE).......................................................
NAKLimit0 Register (Host mode only) (HOST_NAKLIMIT0) ........................................................
Transmit Interval Register (Host mode only) (HOST_TXINTERVAL)..............................................
Receive Type Register (Host mode only) (HOST_RXTYPE) .......................................................
Receive Interval Register (Host mode only) (HOST_RXINTERVAL) ..............................................
Configuration Data Register (CONFIGDATA).........................................................................
Transmit and Receive FIFO Register for Endpoint 0 (FIFO0) ......................................................
Transmit and Receive FIFO Register for Endpoint 1 (FIFO1) ......................................................
Transmit and Receive FIFO Register for Endpoint 2 (FIFO2) ......................................................
Transmit and Receive FIFO Register for Endpoint 3 (FIFO3) ......................................................
Transmit and Receive FIFO Register for Endpoint 4 (FIFO4) ......................................................
OTG Device Control Register (DEVCTL) ..............................................................................
Transmit Endpoint FIFO Size (TXFIFOSZ) ............................................................................
Receive Endpoint FIFO Size (RXFIFOSZ) ............................................................................
Transmit Endpoint FIFO Address (TXFIFOADDR) ...................................................................
Receive Endpoint FIFO Address (RXFIFOADDR) ...................................................................
Transmit Function Address (TXFUNCADDR) .........................................................................
Transmit Hub Address (TXHUBADDR) ................................................................................
Transmit Hub Port (TXHUBPORT) .....................................................................................
Receive Function Address (RXFUNCADDR) .........................................................................
Receive Hub Address (RXHUBADDR) ................................................................................
Receive Hub Port (RXHUBPORT) .....................................................................................
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List of Figures
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List of Tables
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USB Terminal Functions .................................................................................................. 23
PERI_TXCSR Register Bit Configuration for Bulk IN Transactions ................................................. 38
PERI_RXCSR Register Bit Configuration for Bulk OUT Transactions .............................................. 40
PERI_TXCSR Register Bit Configuration for Isochronous IN Transactions ........................................ 42
PERI_RXCSR Register Bit Configuration for Isochronous OUT Transactions ..................................... 44
Transmit Buffer Descriptor Word 0 ....................................................................................... 59
Transmit Buffer Descriptor Word 1 ....................................................................................... 59
Transmit Buffer Descriptor Word 2 ....................................................................................... 59
Transmit Buffer Descriptor Word 3 ....................................................................................... 59
Receive Buffer Descriptor Word 0 ....................................................................................... 64
Receive Buffer Descriptor Word 1 ....................................................................................... 64
Receive Buffer Descriptor Word 2 ....................................................................................... 64
Receive Buffer Descriptor Word 3 ....................................................................................... 65
Interrupts Generated by the USB Controller ............................................................................ 69
USB Interrupt Conditions .................................................................................................. 69
Universal Serial Bus (USB) Registers ................................................................................... 73
Control Register (CTRLR) Field Descriptions .......................................................................... 80
Status Register (STATR) Field Descriptions............................................................................ 80
RNDIS Register (RNDISR) Field Descriptions ......................................................................... 81
Auto Request Register (AUTOREQ) Field Descriptions .............................................................. 82
USB Interrupt Source Register (INTSRCR) Field Descriptions ...................................................... 83
USB Interrupt Source Set Register (INTSETR) Field Descriptions .................................................. 84
USB Interrupt Source Clear Register (INTCLRR) Field Descriptions ............................................... 85
USB Interrupt Mask Register (INTMSKR) Field Descriptions ........................................................ 86
USB Interrupt Mask Set Register (INTMSKSETR) Field Descriptions .............................................. 87
USB Interrupt Mask Clear Register (INTMSKCLRR) Field Descriptions............................................ 88
USB Interrupt Source Masked Register (INTMASKEDR) Field Descriptions ...................................... 89
USB End of Interrupt Register (EOIR) Field Descriptions ............................................................ 90
USB Interrupt Vector Register (INTVECTR) Field Descriptions...................................................... 90
Transmit CPPI Control Register (TCPPICR) Field Descriptions ..................................................... 91
Transmit CPPI Teardown Register (TCPPITDR) Field Descriptions ................................................ 91
Transmit CPPI DMA Controller End of Interrupt Register (TCPPIEOIR) Field Descriptions ..................... 92
Transmit CPPI DMA Controller Interrupt Vector Register (TCPPIIVECTR) Field Descriptions .................. 92
Transmit CPPI Masked Status Register (TCPPIMSKSR) Field Descriptions ...................................... 93
Transmit CPPI Raw Status Register (TCPPIRAWSR) Field Descriptions .......................................... 93
Transmit CPPI Interrupt Enable Set Register (TCPPIIENSETR) Field Descriptions .............................. 94
Transmit CPPI Interrupt Enable Clear Register (TCPPIIENCLRR) Field Descriptions ........................... 94
Receive CPPI Control Register (RCPPICR) Field Descriptions...................................................... 95
Receive CPPI Masked Status Register (RCPPIMSKSR) Field Descriptions ....................................... 95
Receive CPPI Raw Status Register (RCPPIRAWSR) Field Descriptions .......................................... 96
Receive CPPI Interrupt Enable Set Register (RCPPIENSETR) Field Descriptions ............................... 96
Receive CPPI Interrupt Enable Clear Register (RCPPIIENCLRR) Field Descriptions ............................ 97
Receive Buffer Count 0 Register (RBUFCNT0) Field Descriptions.................................................. 97
Receive Buffer Count 1 Register (RBUFCNT1) Field Descriptions.................................................. 98
Receive Buffer Count 2 Register (RBUFCNT2) Field Descriptions.................................................. 98
Receive Buffer Count 3 Register (RBUFCNT3) Field Descriptions.................................................. 99
Transmit CPPI DMA State Word 0 (TCPPIDMASTATEW0) Field Descriptions ................................... 99
Transmit CPPI DMA State Word 1 (TCPPIDMASTATEW1) Field Descriptions .................................. 100
Transmit CPPI DMA State Word 2 (TCPPIDMASTATEW2) Field Descriptions .................................. 101
List of Tables
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Transmit CPPI DMA State Word 3 (TCPPIDMASTATEW3) Field Descriptions ..................................
Transmit CPPI DMA State Word 4 (TCPPIDMASTATEW4) Field Descriptions ..................................
Transmit CPPI DMA State Word 5 (TCPPIDMASTATEW5) Field Descriptions ..................................
Transmit CPPI Completion Pointer (TCPPICOMPPTR) Field Descriptions.......................................
Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0) Field Descriptions ..................................
Receive CPPI DMA State Word 1 (RCPPIDMASTATEW1) Field Descriptions ..................................
Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2) Field Descriptions ..................................
Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3) Field Descriptions ..................................
Receive CPPI DMA State Word 4 (RCPPIDMASTATEW4) Field Descriptions ..................................
Receive CPPI DMA State Word 5 (RCPPIDMASTATEW5) Field Descriptions ..................................
Receive CPPI DMA State Word 6 (RCPPIDMASTATEW6) Field Descriptions ..................................
Receive CPPI Completion Pointer (RCPPICOMPPTR) Field Descriptions .......................................
Function Address Register (FADDR) Field Descriptions ............................................................
Power Management Register (POWER) Field Descriptions ........................................................
Interrupt Register for Endpoint 0 Plus Transmit Endpoints 1 to 4 (INTRTX) Field Descriptions ...............
Interrupt Register for Receive Endpoints 1 to 4 (INTRRX) Field Descriptions ...................................
Interrupt Enable Register for INTRTX (INTRTXE) Field Descriptions .............................................
Interrupt Enable Register for INTRRX (INTRRXE) Field Descriptions .............................................
Interrupt Register for Common USB Interrupts (INTRUSB) Field Descriptions ..................................
Interrupt Enable Register for INTRUSB (INTRUSBE) Field Descriptions .........................................
Frame Number Register (FRAME) Field Descriptions ...............................................................
Index Register for Selecting the Endpoint Status and Control Registers (INDEX) Field Descriptions ........
Register to Enable the USB 2.0 Test Modes (TESTMODE) Field Descriptions ..................................
Maximum Packet Size for Peripheral/Host Transmit Endpoint (TXMAXP) Field Descriptions .................
Control Status Register for Endpoint 0 in Peripheral Mode (PERI_CSR0) Field Descriptions .................
Control Status Register for Endpoint 0 in Host Mode (HOST_CSR0) Field Descriptions .......................
Control Status Register for Peripheral Transmit Endpoint (PERI_TXCSR) Field Descriptions.................
Control Status Register for Host Transmit Endpoint (HOST_TXCSR) Field Descriptions ......................
Maximum Packet Size for Peripheral Host Receive Endpoint (RXMAXP) Field Descriptions ..................
Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR) Field Descriptions .................
Control Status Register for Host Receive Endpoint (HOST_RXCSR) Field Descriptions.......................
Count 0 Register (COUNT0) Field Descriptions ......................................................................
Receive Count Register (RXCOUNT) Field Descriptions ...........................................................
Type Register (Host mode only) (HOST_TYPE0) Field Descriptions .............................................
Transmit Type Register (Host mode only) (HOST_TXTYPE) Field Descriptions ................................
NAKLimit0 Register (Host mode only) (HOST_NAKLIMIT0) Field Descriptions .................................
Transmit Interval Register (Host mode only) (HOST_TXINTERVAL) Field Descriptions .......................
Receive Type Register (Host mode only) (HOST_RXTYPE) Field Descriptions .................................
Receive Interval Register (Host mode only) (HOST_RXINTERVAL) Field Descriptions ........................
Configuration Data Register (CONFIGDATA) Field Descriptions ..................................................
Transmit and Receive FIFO Register for Endpoint 0 (FIFO0) Field Descriptions ................................
Transmit and Receive FIFO Register for Endpoint 1 (FIFO1) Field Descriptions ................................
Transmit and Receive FIFO Register for Endpoint 2 (FIFO2) Field Descriptions ................................
Transmit and Receive FIFO Register for Endpoint 3 (FIFO3) Field Descriptions ................................
Transmit and Receive FIFO Register for Endpoint 4 (FIFO4) Field Descriptions ................................
OTG Device Control Register (DEVCTL) Field Descriptions .......................................................
Transmit Endpoint FIFO Size (TXFIFOSZ) Field Descriptions .....................................................
Receive Endpoint FIFO Size (RXFIFOSZ) Field Descriptions ......................................................
Transmit Endpoint FIFO Address (TXFIFOADDR) Field Descriptions.............................................
Receive Endpoint FIFO Address (RXFIFOADDR) Field Descriptions .............................................
Transmit Function Address (TXFUNCADDR) Field Descriptions ..................................................
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List of Tables
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109
109
110
111
111
112
112
113
114
115
115
116
117
118
119
120
121
122
123
124
125
125
126
126
127
127
128
129
130
131
132
132
133
133
134
135
135
136
136
137
9
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101
102
103
104
105
10
Transmit Hub Address (TXHUBADDR) Field Descriptions ..........................................................
Transmit Hub Port (TXHUBPORT) Field Descriptions ...............................................................
Receive Function Address (RXFUNCADDR) Field Descriptions ...................................................
Receive Hub Address (RXHUBADDR) Field Descriptions ..........................................................
Receive Hub Port (RXHUBPORT) Field Descriptions ...............................................................
List of Tables
137
137
138
138
138
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Preface
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This document describes the Universal Serial Bus (USB) on the TMS320DM335 Digital Media
System-on-Chip (DMSoC).
Notational Conventions
This document uses the following conventions.
• Hexadecimal numbers are shown with the suffix h. For example, the following number is 40
hexadecimal (decimal 64): 40h.
• Registers in this document are shown in figures and described in tables.
– Each register figure shows a rectangle divided into fields that represent the fields of the register.
Each field is labeled with its bit name, its beginning and ending bit numbers above, and its
read/write properties below. A legend explains the notation used for the properties.
– Reserved bits in a register figure designate a bit that is used for future device expansion.
Related Documentation from Texas Instruments
The following documents describe the TMS320DM335 Digital Media System-on-Chip (DMSoC). Copies of
these documents are available on the internet at www.ti.com.
SPRUFX7 — TMS320DM335 Digital Media System-on-Chip (DMSoC) ARM Subsystem Reference
Guide This document describes the ARM Subsystem in the TMS320DM335 Digital Media
System-on-Chip (DMSoC). The ARM subsystem is designed to give the ARM926EJ-S (ARM9)
master control of the device. In general, the ARM is responsible for configuration and control of the
device; including the components of the ARM Subsystem, the peripherals, and the external
memories.
SPRUFX8 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Video Processing Front End
(VPFE) Reference Guide This document describes the Video Processing Front End (VPFE) in the
TMS320DM335 Digital Media System-on-Chip (DMSoC).
SPRUFX9 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Video Processing Back End
(VPBE) Reference Guide This document describes the Video Processing Back End (VPBE) in the
TMS320DM335 Digital Media System-on-Chip (DMSoC).
SPRUFY0 — TMS320DM335 Digital Media System-on-Chip (DMSoC) 64-bit Timer Reference Guide
This document describes the operation of the software-programmable 64-bit timers in the
TMS320DM335 Digital Media System-on-Chip (DMSoC). Timer 0, Timer 1, and Timer 3 are used
as general-purpose (GP) timers and can be programmed in 64-bit mode, dual 32-bit unchained
mode, or dual 32-bit chained mode; Timer 2 is used only as a watchdog timer. The GP timer modes
can be used to generate periodic interrupts or enhanced direct memory access (EDMA)
synchronization events and Real Time Output (RTO) events (Timer 3 only). The watchdog timer
mode is used to provide a recovery mechanism for the device in the event of a fault condition, such
as a non-exiting code loop.
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11
Related Documentation from Texas Instruments
www.ti.com
SPRUFY1 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Serial Peripheral Interface (SPI)
Reference Guide This document describes the serial peripheral interface (SPI) in the
TMS320DM335 Digital Media System-on-Chip (DMSoC). The SPI is a high-speed synchronous
serial input/output port that allows a serial bit stream of programmed length (1 to 16 bits) to be
shifted into and out of the device at a programmed bit-transfer rate. The SPI is normally used for
communication between the DMSoC and external peripherals. Typical applications include an
interface to external I/O or peripheral expansion via devices such as shift registers, display drivers,
SPI EPROMs and analog-to-digital converters.
SPRUFY2 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Universal Asynchronous
Receiver/Transmitter (UART) Reference Guide This document describes the universal
asynchronous receiver/transmitter (UART) peripheral in the TMS320DM335 Digital Media
System-on-Chip (DMSoC). The UART peripheral performs serial-to-parallel conversion on data
received from a peripheral device, and parallel-to-serial conversion on data received from the CPU.
SPRUFY3 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Inter-Integrated Circuit (I2C)
Peripheral Reference Guide This document describes the inter-integrated circuit (I2C) peripheral
in the TMS320DM335 Digital Media System-on-Chip (DMSoC). The I2C peripheral provides an
interface between the DMSoC and other devices compliant with the I2C-bus specification and
connected by way of an I2C-bus. External components attached to this 2-wire serial bus can
transmit and receive up to 8-bit wide data to and from the DMSoC through the I2C peripheral. This
document assumes the reader is familiar with the I2C-bus specification.
SPRUFY5 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Multimedia Card (MMC)/Secure
Digital (SD) Card Controller Reference Guide This document describes the multimedia card
(MMC)/secure digital (SD) card controller in the TMS320DM335 Digital Media System-on-Chip
(DMSoC). The MMC/SD card is used in a number of applications to provide removable data
storage. The MMC/SD controller provides an interface to external MMC and SD cards. The
communication between the MMC/SD controller and MMC/SD card(s) is performed by the MMC/SD
protocol.
SPRUFY6 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Pulse-Width Modulator (PWM)
Reference Guide This document describes the pulse-width modulator (PWM) peripheral in the
TMS320DM335 Digital Media System-on-Chip (DMSoC).
SPRUFY7 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Real-Time Out (RTO) Controller
Reference Guide This document describes the Real Time Out (RTO) controller in the
TMS320DM335 Digital Media System-on-Chip (DMSoC).
SPRUFY8 — TMS320DM335 Digital Media System-on-Chip (DMSoC) General-Purpose Input/Output
(GPIO) Reference Guide This document describes the general-purpose input/output (GPIO)
peripheral in the TMS320DM335 Digital Media System-on-Chip (DMSoC). The GPIO peripheral
provides dedicated general-purpose pins that can be configured as either inputs or outputs. When
configured as an input, you can detect the state of the input by reading the state of an internal
register. When configured as an output, you can write to an internal register to control the state
driven on the output pin.
SPRUFY9 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Universal Serial Bus (USB)
Controller Reference Guide This document describes the universal serial bus (USB) controller in
the TMS320DM335 Digital Media System-on-Chip (DMSoC). The USB controller supports data
throughput rates up to 480 Mbps. It provides a mechanism for data transfer between USB devices
and also supports host negotiation.
SPRUFZ0 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Enhanced Direct Memory
Access (EDMA) Controller Reference Guide This document describes the operation of the
enhanced direct memory access (EDMA3) controller in the TMS320DM335 Digital Media
System-on-Chip (DMSoC). The EDMA controller's primary purpose is to service user-programmed
data transfers between two memory-mapped slave endpoints on the DMSoC.
12
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Related Documentation from Texas Instruments
SPRUFZ1 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Asynchronous External
Memory Interface (EMIF) Reference Guide This document describes the asynchronous external
memory interface (EMIF) in the TMS320DM335 Digital Media System-on-Chip (DMSoC). The EMIF
supports a glueless interface to a variety of external devices.
SPRUFZ2 — TMS320DM335 Digital Media System-on-Chip (DMSoC) DDR2/Mobile DDR
(DDR2/mDDR) Memory Controller Reference Guide This document describes the DDR2/mDDR
memory controller in the TMS320DM335 Digital Media System-on-Chip (DMSoC). The
DDR2/mDDR memory controller is used to interface with JESD79D-2A standard compliant DDR2
SDRAM and mobile DDR devices.
SPRUFZ3 — TMS320DM335 Digital Media System-on-Chip (DMSoC) Audio Serial Port (ASP)
Reference Guide This document describes the operation of the audio serial port (ASP) audio
interface in the TMS320DM335 Digital Media System-on-Chip (DMSoC). The primary audio modes
that are supported by the ASP are the AC97 and IIS modes. In addition to the primary audio
modes, the ASP supports general serial port receive and transmit operation, but is not intended to
be used as a high-speed interface.
Trademarks
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13
Reference Guide
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Universal Serial Bus (USB) Controller
1
Introduction
This document describes the universal serial bus (USB) controller in the TMS320DM335 Digital Media
System-on-Chip (DMSoC). The controller complies with the USB 2.0 standard high-speed and full-speed
functions and low-speed, full-speed, and high-speed limited host mode operations. It also includes support
for the Session Request and Host Negotiation Protocols used in point-to-point communications, details of
which are given in the USB On-The-Go supplement to the USB 2.0 specification. In addition, the four test
modes for high-speed operation described in the USB 2.0 specification. It also allows options that allow it
to be forced into full-speed mode, high-speed mode, or host mode which may be used in helping debug
PHY problems in hardware.
1.1
Purpose of the Peripheral
The USB controller supports data throughput rates up to 480 Mbps. It provides a mechanism for data
transfer between USB devices and also supports host negotiation.
1.2
Features
The USB has the following features:
• Supports USB 2.0 peripheral at High Speed (480 Mbps) and Full Speed (12 Mbps)
• Supports USB 2.0 host at High Speed (480 Mbps), Full Speed (12 Mbps), and Low Speed (1.5 Mbps)
• Supports 4 simultaneous RX and TX endpoints, more can be supported by dynamically switching
• Each endpoint can support all transfer types (control, bulk, interrupt, and isochronous)
• Supports USB extensions for Session Request (SRP) and Host Negotiation (HNP)
• Includes a 4K endpoint FIFO RAM, and supports programmable FIFO sizes
• External 5V power supply for VBUS can be controlled through I2C
• Includes a DMA controller that supports 4 TX and 4 RX DMA channels
• Includes RNDIS mode of DMA for accelerating RNDIS type protocols using short packet termination
over USB
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1.3
Functional Block Diagram
The USB functional block diagram is shown in Figure 1.
Figure 1. Functional Block Diagram
Internal
bus
CPPI
DMA
engine
FIFO
Packet
encode/
decode
Registers, interrupts, endpoint control,
and packet scheduling
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USB
2.0
PHY
USB
Crystal
oscillator
Universal Serial Bus (USB) Controller
15
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Supported Use Case Examples
The USB supports the following user cases:
Detailed information about the architecture and operation of the USB controller follows in Section 2.
Programming examples are also provided for each of the operational modes of the controller.
User Case 1: An example of how to initialize the USB controller
Example 1. Initializing the USB Controller
// Routine to initialize USB controller
void usb_init()
{
// local loop variable
int I;
// VBUS must be controlled externally. The following routine
// should perform whatever actions are required (if any) to
// turn off VBUS in the system.
vbus_off();
// Reset the USB controller
usbRegs->CTRLR = 0x00000001;
// Power on PHY and oscillator by clearing bits 2, 1, and 0 of USB_PHY_CTL
sysRegs->USB_PHY_CTRL = 0x000000D0;
//Clear all pending interrupts
usbRegs->INTCLRR = usbRegs->INTSRCR;
// Initialize CPPI DMA
usbRegs->RCPPICR = 0;
usbRegs->TCPPICR = 0;
//Disable the RX DMA
//Disable the TX DMA
// Initialize CPPI DMA state
for(I = 0; i<4; I++) {
usbRegs->CHANNEL[i].TCPPIDMASTATEW0
usbRegs->CHANNEL[i].TCPPIDMASTATEW1
usbRegs->CHANNEL[i].TCPPIDMASTATEW2
usbRegs->CHANNEL[i].TCPPIDMASTATEW3
usbRegs->CHANNEL[i].TCPPIDMASTATEW4
usbRegs->CHANNEL[i].TCPPIDMASTATEW5
usbRegs->CHANNEL[i].RCPPIDMASTATEW0
usbRegs->CHANNEL[i].RCPPIDMASTATEW1
usbRegs->CHANNEL[i].RCPPIDMASTATEW2
usbRegs->CHANNEL[i].RCPPIDMASTATEW3
usbRegs->CHANNEL[i].RCPPIDMASTATEW4
usbRegs->CHANNEL[i].RCPPIDMASTATEW5
usbRegs->CHANNEL[i].RCPPIDMASTATEW6
}
=
=
=
=
=
=
=
=
=
=
=
=
=
0;
0;
0;
0;
0;
0;
0;
0;
0;
0;
0;
0;
0;
}
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User Case 2: An example of how to program the USB Endpoints in peripheral mode
Example 2. Programming the USB Endpoints in Peripheral Mode
// DMA channel number.
int CHAN_NUM = 0;
//
//
//
//
//
//
//
//
//
//
//
Valid values are 0, 1, 2, or 3.
Fifo sizes: uncomment the desired size.
This example uses 64-byte fifo.
int fifosize = 0;
// 8 bytes
int fifosize = 1;
// 16 bytes
int fifosize = 2;
// 32 bytes
int fifosize = 3;
// 64 bytes
int fifosize = 4;
// 128 bytes
int fifosize = 5;
// 256 bytes
int fifosize = 6;
// 512 bytes
int fifosize = 7;
// 1024 bytes
int fifosize = 8;
// 2048 bytes
int fifosize = 9;
// 4096 bytes
// FIFO address. Leave 64-bytes for endpoint 0.
int fifo_start_address = 8;
// Uncomment the desired buffering. If double-buffer is selected, actual
// FIFO space will be twice the value listed above for fifosize.
// This example uses single buffer.
int double_buffer = 0; // Single-buffer
// int double_buffer = 1; // Double-buffer
// For maximum packet size this formula will usually work, but it can also be
// set to another value if needed. If non power of 2 value is needed (such as
// 1023) set it explicitly.
#define FIFO_MAXP 8*(1<<fifosize);
// Set the following variable to the device address.
int device_address = 0;
// The following code should be run after receiving a USB reset from the host.
// Initialize the endpoint FIFO. RX and TX will be allocated the same sizes.
usbRegs->INDEX = CHAN_NUM+1;
usbRegs->RXFIFOSZ = fifosize | ((double_buffer & 1)<<4);
usbRegs->RXFIFOADDR = fifo_start_address;
usbRegs->TXFIFOSZ =
fifosize | ((double_buffer & 1)<<4);
usbRegs->TXFIFOADDR = fifo_start_address + (1<<(fifosize+double_buffer));
usbRegs->RXMAXP = FIFO_MAXP;
usbRegs->TXMAXP = FIFO_MAXP;
// Force Data Toggle is optional for interrupt traffic. Uncomment if needed.
// CSL_FINS(usbRegs->PERI_TXCSR,USB_PERI_TXCSR_FRCDATATOG,1);
//
//
//
//
Uncomment below to configure the endpoint for ISO and not respond with a
handshake packet.
CSL_FINS(usbRegs->PERI_RXCSR,USB_PERI_RXCSR_ISO,1);
CSL_FINS(usbRegs->PERI_TXCSR,USB_PERI_TXCSR_ISO,1);
// After receiving a successful set-address command, set the following register
// to the specified address immediately following the status stage.
USBREGS->FADDR = device_address;
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User Case 3: An example of how to program the USB endpoints in host mode
Example 3. Programming the USB Endpoints in Host Mode
// DMA channel number.
int CHAN_NUM = 0;
//
//
//
//
//
//
//
//
//
//
//
Valid values are 0, 1, 2, or 3.
Fifo sizes: uncomment the desired size.
This example uses 64-byte fifo.
int fifosize = 0;
// 8 bytes
int fifosize = 1;
// 16 bytes
int fifosize = 2;
// 32 bytes
int fifosize = 3;
// 64 bytes
int fifosize = 4;
// 128 bytes
int fifosize = 5;
// 256 bytes
int fifosize = 6;
// 512 bytes
int fifosize = 7;
// 1024 bytes
int fifosize = 8;
// 2048 bytes
int fifosize = 9;
// 4096 bytes
// FIFO address. Leave 64-bytes for endpoint 0.
int fifo_start_address = 8;
// Uncomment the desired buffering. If double-buffer is selected, actual
// FIFO space will be twice the value listed above for fifosize.
// This example uses single buffer.
int double_buffer = 0; // Single-buffer
// int double_buffer = 1; // Double-buffer
// Set the following variable to the device endpoint type: CONTROL ISO BULK or IN
int device_protocol = BULK;
//int device_protocol = ISO;
//int device_protocol = INT;
// USB speeds
#define LOW_SPEED 0
#define FULL_SPEED 1
#define HIGH_SPEED 2
// TXTYPE protocol
#define CONTROL 0
#define ISO 1
#define BULK 2
#define INT 3
// For maximum packet size this formula will usually work, but it can also be
// set to another value if needed. If non power of 2 value is needed (such as
// 1023) set it explicitly.
#define FIFO_MAXP 8*(1<<fifosize);
// Set the following variable to the device address.
int device_address = 1;
// Set the following variable to the device endpoint number.
int device_ep = 1;
// Variable used for endpoint configuration
Uint8 type = 0;
// Variable to keep track of errors
int error = 0;
// The following code should be run after resetting the attached device
// Initialize the endpoint FIFO. RX and TX will be allocated the same sizes.
usbRegs->INDEX = CHAN_NUM+1;
usbRegs->RXFIFOSZ = fifosize | ((double_buffer & 1)<<4);
usbRegs->RXFIFOADDR = fifo_start_address;
usbRegs->TXFIFOSZ =
fifosize | ((double_buffer & 1)<<4);
usbRegs->TXFIFOADDR = fifo_start_address + (1<<(fifosize+double_buffer));
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Example 3. Programming the USB Endpoints in Host Mode (continued)
usbRegs->RXMAXP = FIFO_MAXP;
usbRegs->TXMAXP = FIFO_MAXP;
//Configure the endpoint
switch (device_speed) {
case LOW_SPEED : type = (3<<6) | ((device_protocol & 3) << 4) | (device_ep & 0xf); break;
case FULL_SPEED: type = (2<<6) | ((device_protocol & 3) << 4) | (device_ep & 0xf); break;
case HIGH_SPEED: type = (1<<6) | ((device_protocol & 3) << 4) | (device_ep & 0xf); break;
default:error++;
}
usbRegs->EPCSR[CHAN_NUM+1].HOST_TYPE0 = type; // TXTYPE
usbRegs->EPCSR[CHAN_NUM+1].HOST_RXTYPE = type;
// Set NAK limit / Polling interval (Interrupt & Iso protocols)
if ((device_protocol == INT) || (device_protocol == ISO)) {
usbRegs->EPCSR[CHAN_NUM+1].HOST_NAKLIMIT0 = TXINTERVAL;
// TX Polling interval
usbRegs->EPCSR[CHAN_NUM+1].HOST_RXINTERVAL = RXINTERVAL;
// RX Polling interval
} else {
usbRegs->EPCSR[CHAN_NUM+1].HOST_NAKLIMIT0 = 2;
// Frames to timeout from NAKs
usbRegs->EPCSR[CHAN_NUM+1].HOST_RXINTERVAL = 2;
// Frames to timeout from NAKs
}
//Set the address for transactions after SET ADDRESS successfully completed
usbRegs->EPTRG[CHAN_NUM+1].TXFUNCADDR = device_address;
usbRegs->EPTRG[CHAN_NUM+1].RXFUNCADDR = device_address;
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User Case 4: An example of how to do host negotiation to support USB
If the HOSTREQ bit in the DEVCTL register is set, host negotiation is performed by the hardware when
the device enters suspend mode. The bit is cleared when host negotiation is complete.
User Case 5: An example of how to program the USB DMA controller
Example 4. Programming the USB DMA Controller
// Number of DMA channels
#define NUM_CHANNEL 4
// Number of DMA buffers to allocate
#define RX_BUFFERS 32
#define TX_BUFFERS 32
// Memory region to place DMA buffers and descriptors
#define MEMORY_TARGET ".DDREMIF_0_BUF"
// DMA defines
#define SOP
#define EOP
#define OWNER
#define EOQ
#define ZERO_BYTE
#define RX_ABORT
(Uint32) (1<<31)
(Uint32) (1<<30)
(Uint32) (1<<29)
(Uint32) (1<<28)
(Uint32) (1<<23)
(Uint32) (1<<19)
// DMA channel configuration
#define CH0 0
#define CH1 1
#define CH2 2
#define CH3 3
// Loop variable
int I;
// Variable to keep track of errors
int error = 0;
// Variable to keep track of the number of descriptors built
int tx_desc[NUM_CHANNEL];
// Current TX Buffer descriptor[channel number]
int rx_desc[NUM_CHANNEL];
// Current RX Buffer descriptor[channel number]
// Separate data section for bufferDesc. NOTE: CPPI buffers MUST be aligned to 16-byte
boundaries.
#pragma DATA_SECTION(rx_bufferDesc, MEMORY_TARGET)
Uint32 rx_bufferDesc[NUM_CHANNEL][RX_BUFFERS];
#pragma DATA_SECTION(tx_bufferDesc, MEMORY_TARGET)
Uint32 tx_bufferDesc[NUM_CHANNEL][TX_BUFFERS];
// Initialize CPPI DMA. This code is also included in the controller initialization.
usbRegs->RCPPICR = 0;
//Disable the RX DMA
usbRegs->TCPPICR = 0;
//Disable the TX DMA
for(I = 0; i<NUM_CHANNEL;i++) { // Initialize CPPI DMA state
usbRegs->CHANNEL[i].TCPPIDMASTATEW0 = 0;
usbRegs->CHANNEL[i].TCPPIDMASTATEW1 = 0;
usbRegs->CHANNEL[i].TCPPIDMASTATEW2 = 0;
usbRegs->CHANNEL[i].TCPPIDMASTATEW3 = 0;
usbRegs->CHANNEL[i].TCPPIDMASTATEW4 = 0;
usbRegs->CHANNEL[i].TCPPIDMASTATEW5 = 0;
usbRegs->CHANNEL[i].RCPPIDMASTATEW0 = 0;
usbRegs->CHANNEL[i].RCPPIDMASTATEW1 = 0;
usbRegs->CHANNEL[i].RCPPIDMASTATEW2 = 0;
usbRegs->CHANNEL[i].RCPPIDMASTATEW3 = 0;
usbRegs->CHANNEL[i].RCPPIDMASTATEW4 = 0;
usbRegs->CHANNEL[i].RCPPIDMASTATEW5 = 0;
usbRegs->CHANNEL[i].RCPPIDMASTATEW6 = 0;
tx_desc[i] = 0;
rx_desc[i] = 0;
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Example 4. Programming the USB DMA Controller (continued)
}
// Routine to flush TX fifo.
// Must call this routine twice for double-buffered FIFO
void flush_tx_fifo(int ep) {
int index_save;
int status;
index_save = usbRegs->INDEX;
usbRegs->INDEX = ep;
status = usbRegs->PERI_TXCSR & 3;
if (!(status)) {
usbRegs->PERI_TXCSR |= 1;
packet already in FIFO
}
// Save the index to restore later
// Set the index to the desired endpoint
// Isolate the TxPktRdy and FIFONotEmpty bits
// Nothing showing in FIFO
// Set TxPktRdy in case there is a partial
usbRegs->PERI_TXCSR = ((usbRegs->PERI_TXCSR & 0xFFFC) | 8);
// Write TXCSR with flush
bit set, FIFONotEmpty=0, and TxPktRdy=0.
while (usbRegs->PERI_TXCSR & 8);
// Keep looping until the flush bit clears
usbRegs->INDEX = index_save;
// Restore the index to previous value
}
// Routine to start the TX DMA for a given channel
void start_tx_dma(int ch) {
// Must have at least one descriptor before turning on TX DMA
if (rx_desc[ch] < 1) {error++;} else {
//Flush FIFO (2 times in case it is double-buffered)
flush_tx_fifo(ch+1);
flush_tx_fifo(ch+1);
// Start the DMA
usbRegs->TCPPICR = 1; //Enable Tx CPPI DMA
usbRegs->CHANNEL[ch].TCPPIDMASTATEW0 = (Uint32)(&tx_bufferDesc[ch][0]);
CSL_FINS(usbRegs->PERI_TXCSR,USB_PERI_TXCSR_DMAEN,1);
// TXCSR, bit DMAReqEnab
}
}
// Routine to add a TX descriptor
void add_tx_descriptor(int ch, unsigned char * inBuf, int bytes) {
if ((bytes < 0) || (bytes >65535)) {bytes = 64; error++;}
// Link previous buffer to this one if this is not the first descriptor of the channel
if (tx_desc[ch] > 0) tx_bufferDesc[ch][4*(tx_desc[ch]-1)] =
(Uint32)(&tx_bufferDesc[ch][4*tx_desc[ch]]);
// Set up DMA buffer descriptors
tx_bufferDesc[ch][4*tx_desc[ch]+0] = (Uint32)(0x00000000);
// Next Descriptor pointer
tx_bufferDesc[ch][4*tx_desc[ch]+1] = (Uint32)inBuf;
// Buffer pointer
tx_bufferDesc[ch][4*tx_desc[ch]+2] = (0x0000 << 16) | bytes;
// [31:16] Buffer offset
[15:0] Buffer length
if (bytes == 0) bytes = ZERO_BYTE | 1;
// Set the ZERO_BYTE bit and size 1 byte
tx_bufferDesc[ch][4*tx_desc[ch]+3] = SOP | EOP | OWNER | bytes;
// [31]=SOP, [30]=EOP,
[29]=owner, [28]=EOQ, [23]=zero-byte, [19] = rxabort, [15:0]=packet length
// If DMA already enabled and has stopped, write this to the TX Queue head pointer
if ((usbRegs->TCPPICR == 1) && (usbRegs->CHANNEL[ch].TCPPIDMASTATEW0 == 0))
usbRegs->CHANNEL[ch].TCPPIDMASTATEW0 = (Uint32)(&tx_bufferDesc[ch][4*tx_desc[ch]+0]);
// Increment descriptor counter
tx_desc[ch]++;
}
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Example 4. Programming the USB DMA Controller (continued)
// Routine to start the RX DMA for a given channel
void start_rx_dma(int ch) {
int index_save;
index_save = usbRegs->INDEX;
// Save the index to restore later
// Must have at least 3 descriptors to receive anything
if (rx_desc[ch] < 2) {error++;} else {
usbRegs->INDEX = ch+1;
usbRegs->RCPPICR = 1; //Enable Rx CPPI DMA
usbRegs->CHANNEL[ch].RCPPIDMASTATEW1 = (Uint32)(&rx_bufferDesc[ch][0]);
CSL_FINS(usbRegs->PERI_RXCSR,USB_PERI_RXCSR_DMAEN,1);
// Update the buffer count register. This ADDS to the existing value, does not
overwrite.
switch (ch) {
case 0: usbRegs->RBUFCNT0 = rx_desc[ch]; break;
case 1: usbRegs->RBUFCNT1 = rx_desc[ch]; break;
case 2: usbRegs->RBUFCNT2 = rx_desc[ch]; break;
case 3: usbRegs->RBUFCNT3 = rx_desc[ch]; break;
}
}
usbRegs->INDEX = index_save;
// Restore the index to previous value
}
//Function to build Rx DMA descriptors
void add_rx_descriptor(int ch, unsigned char * outBuf, int bytes) {
int index_save;
index_save = usbRegs->INDEX;
// Save the index to restore later
if (bytes < 1) {bytes = 64; error++;}
usbRegs->INDEX = ch+1;
// Link previous buffer to this one if this is not the first descriptor of the channel
if (rx_desc[ch] > 0) rx_bufferDesc[ch][4*(rx_desc[ch]-1)] =
(Uint32)(&rx_bufferDesc[ch][4*rx_desc[ch]]);
rx_bufferDesc[ch][4*rx_desc[ch]+0]
rx_bufferDesc[ch][4*rx_desc[ch]+1]
rx_bufferDesc[ch][4*rx_desc[ch]+2]
rx_bufferDesc[ch][4*rx_desc[ch]+3]
rx_desc[ch]++;
usbRegs->INDEX = index_save;
=
=
=
=
(Uint32)(0x00000000);
(Uint32)outBuf;
(0x0000 << 16) | bytes;
OWNER | 0;
// Next descriptor
// Buffer address
// Rx buffer size in bytes
// OWNER
// Restore the index to previous value
}
1.5
Industry Standard(s) Compliance Statement
This device conforms to USB 2.0 Specification and On-The-Go Supplement to the USB 2.0 Specification
Rev 1.0a.
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2
Peripheral Architecture
2.1
Clock Control
The USB controller is driven by two clocks: an output clock of PLL1 (SYSCLK2) which is ARM CPU clock
divided by 3, and an output clock of the USB PHY. For proper USB function, SYSCLK2 must be greater
than 60 MHZ.
The USB PHY takes an input clock that is configurable by the USB PHY clock source bits (PHYCLKSRC)
in the USB PHY control register (USB_PHY_CTL) in the System Control Module. When a 24 MHZ crystal
is used at MXI1/MXO1, set PHYCLKSRC to 0. This will present a 24 MHZ clock to the USB PHY. When a
36 MHZ crystal is used at MXI1/MXO1, set PHYCLKSRC to 1. This will present a 12 MHZ clock (36 MHZ
divided internally by three) to the USB PHY. The USB PHY is capable of accepting only 24 MHZ and 12
MHZ; thus you must use either a 24 MHZ or 36 MHZ crystal at MXI1/MXO1. For detailed information on
device clocking and the USB_PHY_CTL register, see the TMS320DM335 Digital Media System-on-Chip
(DMSoC) ARM Subsystem Reference Guide (SPRUFX7).
2.2
Signal Descriptions
The USB controller provides the following I/O signals. Table 1 shows the USB port pins used in each
mode. For additional information, see the device-specific data manual.
Table 1. USB Terminal Functions
NAME
I/O
(1)
OTHER
DESCRIPTION
USB_DP
A I/O/Z
VDDA33_USB
USB D+ (differential signal pair)
USB_DM
A I/O/Z
VDDA33_USB
USB D- (differential signal pair)
USB_R1
A I/O/Z
USB_ID
A I/O/Z
VDDA33_USB
USB operating mode identification pin For Device mode operation
only, pull up this pin to VDD with a 1.5K ohm resistor. For Host mode
operation only, pull down this pin to ground (VSS) with a 1.5K ohm
resistor. If using an OTG or mini-USB connector, this pin will be set
properly via the cable/connector configuration.
USB_VBUS
A I/O/Z
VDD
Five volt input that signifies that VBUS is connected. The OTG
section of the PHY can also pull up/down on this signal for HNP and
SRP. For device or host mode operation only, pull up this pin to 5v
with a 1K ohm resistor. For host mode operation, tie USB power
signal on USB connector to 5v also. For mixed host / device mode
operation, tie this to the charge pump.
USB_DRVVBUS
I/O/Z
VDD
Digital output to control external 5-V supply
VSS_USB
GND
VDD
Ground for USB reference voltage
VDDA33_USB
I/O/Z
VDD
Analog 3.3 V power USBPHY
VSS_USB
GND
VDD
Ground for USB reference voltage
VDDA33_USB_PLL
I/O/Z
VDD
Common mode 3.3 V power for USB PHY (PLL)
VSS_USB
GND
VDD
Ground for USB reference voltage
VDDA13_USB
I/O/Z
VDD
Analog 1.3 V power for USB PHY
VSS_USB
GND
VDD
Ground for USB reference voltage
VDD
Digital 1.3 V power for USB PHY
VDD
Ground for USB reference voltage
VDDD13_USB
VSS_USB
(1)
GND
USB reference current output
I = Input, O = Output, Z = High Impedance, S = Supply voltage, GND = Ground, A = Analog Signal
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USB_DP / USB_DM Polarity Inversion
You may invert the polarity of the of the USB data pin (USB_DP and USB_DM). Since USB_DP is equal
to the inverse of USB_DM (they form a differential pair), inverting these pins allows you to effectively swap
their function. This allows flexibility in board design by allowing different USB connector configurations. In
particular, this allows for mounting the connector on either side of the board and for arranging the
USB_DP/USB_DM signals so they do not physically cross over each other (so they can be routed
completely on the one surface trace).
To invert USB_DP/USB_DM use the bit DATAPOL in the USB_PHY_CTRL register in the system control
module. For more information on the USB_PHY_CTL register, see the TMS320DM335 Digital Media
System-on-Chip (DMSoC) ARM Subsystem Reference Guide (SPRUFX7).
2.4
Indexed and Non-Indexed Registers
USB controller provides two mechanism of accessing the endpoint control and status registers:
• Indexed Endpoint Control/Status Registers – These registers are memory-mapped at offset 410h to
41Fh. The endpoint is selected by programming the INDEX register of the controller.
• Non-indexed Endpoint Control/Status Registers – These registers are memory-mapped at offset 500h
to 54Fh. Registers at offset 500h-50Fh map to Endpoint 0; offset 510h-51Fh map to Endpoint 1, and
so on.
For detailed information about the USB controller registers, see Section 4.
2.5
USB PHY Initialization
The default state of the USB PHY in powered down state. The external PHY clock frequency should be
determined (it is either 24 MHZ or 36 MHZ) prior to initialization. The USB_PHY_CTL register has all the
bit fields necessary to configure and control the PHY. For more information on the USB_PHY_CTL
register, see the TMS320DM335 Digital Media System-on-Chip (DMSoC) ARM Subsystem Reference
Guide (SPRUFX7).
The following is the recommended step for configuring the USB PHY (note that the entire initialization can
be performed at using single or multiple steps).
• Identify the external input PHY Clock Frequency: Clear USB_PHY_CTL:PHYCLKSRC to 0 for a 24
MHZ clock source in use and set for 36 MHZ clock use.
• Identify if the D+ and D- lines connection matches normal polarity or inverted: Clear
USB_PHY_CTL:DATAPOL to 0 for normal connection and for inverted connection set it to 1.
• Power up PHY: Clear all of the following fields: USB_ PHY_CTL:PHYPDWN, OTGPDWN,
VPSS_OSCPDWN
• Enable Voltage Comparators and set PLL Operation for normal: USB_PHY_CTL:SESNDEN,
VBDTCTEN, PHYPLLON
• Power up PHY and Clock: Clear USB_PHY_CTL:PHYPDWN, OTGPDWN, VPSS_OSCPDWN
• Wait for PHY PLL to lock: USB_PHY_CTL:PHYCLKGD will be set to 1 by the controller when PHY PLL
locks.
2.6
VBUS Voltage Sourcing Control
When the USB Controller assumes the role of a host, it is required to supply a 5V Power to an attached
device through its VBUS line. In order to achieve this task, the USB Controller requires the use of an
external logic (or charge pump) capable of sourcing a 5V power. A USB_DRVVBUS is used as a control
signal to enable/disable the external logic to either source or disable power on the VBUS line. This control
is automatic and is handled by the controller. The USB Controller drives the USB_DRVVBUS signal high
when it assumes the role of a host while the controller is in Session. When assuming the role of a device,
the controller drives USB_DRVVBUS low disabling the external charge pump; hence no power is driven
on the VBUS line.
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2.7
Dynamic FIFO Sizing
The USB controller supports a total of 4K RAM to dynamically allocate FIFO to all endpoints. The
allocation of FIFO space to the different endpoints requires the specification for each Tx and Rx endpoint
of:
• The start address of the FIFO within the RAM block
• The maximum size of packet to be supported
• Whether double-buffering is required.
These details are specified through four registers, which are added to the indexed area of the memory
map. That is, the registers for the desired endpoint are accessed after programming the INDEX register
with the desired endpoint value. Section 4.80, Section 4.81, Section 4.82, and Section 4.83 provide details
of these registers.
Note:
The option of setting FIFO sizes dynamically only applies to Endpoints 1 … 4. Endpoint 0
FIFO has a fixed size (64 bytes) and a fixed location (start address 0).
It is the responsibility of the firmware to ensure that all the Tx and Rx endpoints that are
active in the current USB configuration have a block of RAM assigned exclusively to that
endpoint that is at least as large as the maximum packet size set for that endpoint.
3
USB Controller Host and Peripheral Modes Operation
The USB controller can be used in a range of different environments. It can be used as either a
high-speed or a full-speed USB peripheral device attached to a conventional USB host (such as a PC). It
can be used as either host or peripheral device in point-to-point data transfers with another peripheral
device - or, if the other device also contains a Dual-Role Controller, the two devices can switch roles as
required. (This second device may be either a high-speed, full-speed or low-speed USB function.) Or the
controller can be used as the host to a range of such peripheral devices in a multi-point setup.
Whether the controller expects to behave as a host or as a peripheral device depends on the way the
devices are cabled together. Each USB cable has an A end and a B end. If the A end of the cable is
plugged into the controller, it will take the role of the Host device and go into host mode. If the B end of
the cable is plugged in, the controller will go instead into peripheral mode.
The USB controller interrupts the ARM on completion of the data transfer on any of the endpoints or on
detecting reset, resume, suspend, connect, disconnect, or SOF on the bus.
When the ARM is interrupted with a USB interrupt, it needs to read the interrupt status register to
determine the endpoints that have caused the interrupt and jump to the appropriate routine. If multiple
endpoints have caused the interrupt, endpoint 0 should be serviced first, followed by the other endpoints.
The suspend interrupt should be serviced last.
The flowchart in Figure 2 describes the interrupt service routine for the USB module.
The following sections describe the programming of USB controller in Peripheral mode and Host mode.
DMA Operations and Interrupt Handler mechanisms are common to both peripheral and host mode
operations and are discussed after the programming in Peripheral and Host Mode.
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Figure 2. Interrupt Service Routine Flow Chart
Read interrupt
status register
Yes
Resume routine
Resume
interrupt
?
No
A device
Session req
routine
Yes
A
device or
B device
?
B device
SESSREQ
interrupt
?
No
Vbus error
routine
Yes
Vbus
error interrupt
?
Host
Connect
routine
Babble
routine
Host EP0
routine
Yes
Yes
Yes
Peripheral
Host
or peripheral
?
Connect
interrupt
?
EP0
interrupt
?
No
No
Babble
interrupt
?
Receive
interrupt
?
No
No
EP0
interrupt
?
Transmit
interrupt
?
Yes
Peripheral
EP0 routine
Yes
Peripheral
Rx routine
Yes
Peripheral
Tx routine
No
Host Rx
routine
Yes
Receive
interrupt
?
No
Host Tx
routine
Yes
Transmit
interrupt
?
No
26
Universal Serial Bus (USB) Controller
SOF
interrupt
?
Yes
Resume
routine
Disconn
interrupt
?
Yes
Disconnect
routine
Suspend
interrupt
?
Yes
Suspend
routine
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3.1
USB Controller Peripheral Mode Operation
•
•
•
•
Soft connect - After a reset, the SOFTCONN bit of POWER register (bit 6) is cleared to 0. The
controller will therefore appear disconnected until the software has set the SOFTCONN bit to 1. The
application software can then choose when to set the PHY into its normal mode. Systems with a
lengthy initialization procedure may use this to ensure that initialization is complete and the system is
ready to perform enumeration before connecting to the USB.
Once the SOFTCONN bit has been set, the software can also simulate a disconnect by clearing this bit
to 0.
Entry into suspend mode
When operating as a peripheral device, the controller monitors activity on the bus and when no activity
has occurred for 3 ms, it goes into Suspend mode. If the Suspend interrupt has been enabled, an
interrupt will be generated at this time.
At this point, the controller can then be left active (and hence able to detect when Resume signaling
occurs on the USB), or the application may arrange to disable the controller by stopping its clock.
However, the controller will not then be able to detect Resume signaling on the USB. As a result, some
external hardware will be needed to detect Resume signaling (by monitoring the DM and DP signals),
so that the clock to the controller can be restarted.
Resume Signaling - When resume signaling occurs on the bus, first the clock to the controller must be
restarted if necessary. Then the controller will automatically exit Suspend mode. If the Resume
interrupt is enabled, an interrupt will be generated.
Initiating a remote wakeup - If the software wants to initiate a remote wakeup while the controller is in
Suspend mode, it should write to the Power register to set the RESUME bit to 1. The software should
leave then this bit set for approximately 10 ms (minimum of 2 ms, a maximum of 15 ms) before
resetting it to 0.
Note:
•
3.1.1
No resume interrupt will be generated when the software initiates a remote wakeup.
Reset Signaling - When reset signaling occurs on the bus, the controller will perform the following
actions:
– Sets FADDR register to 0
– Sets INDEX register to 0
– Flushes all endpoint FIFOs
– Clears all control/status registers
– Generates a reset interrupt.
If the HSENA bit in the POWER register (bit 5) was set, the controller also tries to negotiate for
high-speed operation.
Whether high-speed operation is selected is indicated by HSMODE bit of POWER register (bit 4).
When the application software receives a reset interrupt, it should close any open pipes and wait for
bus enumeration to begin.
Control Transactions
Endpoint 0 is the main control endpoint of the core. The software is required to handle all the standard
device requests that may be sent or received via endpoint 0. These are described in Universal Serial Bus
Specification, Revision 2.0, Chapter 9. The protocol for these device requests involves different numbers
and types of transactions per transfer. To accommodate this, the software needs to take a state machine
approach to command decoding and handling.
The Standard Device Requests received by a USB peripheral device can be divided into three categories:
Zero Data Requests (in which all the information is included in the command), Write Requests (in which
the command will be followed by additional data), and Read Requests (in which the device is required to
send data back to the host).
This section looks at the sequence of actions that the software must perform to process these different
types of device request.
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The Setup packet associated with any standard device request should include an 8-byte
command. Any setup packet containing a command field of anything other than 8 bytes will
be automatically rejected by the controller.
Zero Data Requests
Zero data requests have all their information included in the 8-byte command and require no additional
data to be transferred. Examples of Zero Data standard device requests are:
• SET_FEATURE
• CLEAR_FEATURE
• SET_ADDRESS
• SET_CONFIGURATION
• SET_INTERFACE
The sequence of events will begin, as with all requests, when the software receives an endpoint 0
interrupt. The RXPKTRDY bit of PERI_CSR0 (bit 0) will also have been set. The 8-byte command should
then be read from the endpoint 0 FIFO, decoded and the appropriate action taken.
For example, if the command is SET_ADDRESS, the 7-bit address value contained in the command
should be written to the FADDR register. The PERI_CSR0 register should then be written to set the
SERV_RXPKTRDY bit (bit 6) (indicating that the command has been read from the FIFO) and to set the
DATAEND bit (bit 3) (indicating that no further data is expected for this request). The interval between
setting SERV_RXPKTRDY bit and DATAEND bit should be very small to avoid getting a SetupEnd error
condition.
When the host moves to the status stage of the request, a second endpoint 0 interrupt will be generated to
indicate that the request has completed. No further action is required from the software. The second
interrupt is just a confirmation that the request completed successfully. For SET_ADDRESS command,
the address should be set in FADDR register only after the status stage interrupt is received.
If the command is an unrecognized command, or for some other reason cannot be executed, then when it
has been decoded, the PERI_CSR0 register should be written to set the SERV_RXPKTRDY bit (bit 6) and
to set the SENDSTALL bit (bit 5). When the host moves to the status stage of the request, the controller
will send a STALL to tell the host that the request was not executed. A second endpoint 0 interrupt will be
generated and the SENTSTALL bit (bit 2 of PERI_CSR0) will be set.
If the host sends more data after the DATAEND bit has been set, then the controller will send a STALL.
An endpoint 0 interrupt will be generated and the SENTSTALL bit (bit 2 of PERI_CSR0) will be set.
Note:
3.1.1.2
DMA is not supported for endpoint 0, so the command should be read by accessing the
endpoint 0 FIFO register.
Write Requests
Write requests involve an additional packet (or packets) of data being sent from the host after the 8-byte
command. An example of a Write standard device request is: SET_DESCRIPTOR.
The sequence of events will begin, as with all requests, when the software receives an endpoint 0
interrupt. The RXPKTRDY bit of PERI_CSR0 will also have been set. The 8-byte command should then
be read from the Endpoint 0 FIFO and decoded.
As with a zero data request, the PERI_CSR0 register should then be written to set the SERV_RXPKTRDY
bit (bit 6) (indicating that the command has been read from the FIFO) but in this case the DATAEND bit
(bit 3) should not be set (indicating that more data is expected).
When a second endpoint 0 interrupt is received, the PERI_CSR0 register should be read to check the
endpoint status. The RXPKTRDY bit of PERI_CSR0 should be set to indicate that a data packet has been
received. The COUNT0 register should then be read to determine the size of this data packet. The data
packet can then be read from the endpoint 0 FIFO.
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If the length of the data associated with the request (indicated by the wLength field in the command) is
greater than the maximum packet size for endpoint 0, further data packets will be sent. In this case,
PERI_CSR0 should be written to set the SERV_RXPKTRDY bit, but the DATAEND bit should not be set.
When all the expected data packets have been received, the PERI_CSR0 register should be written to set
the SERV_RXPKTRDY bit and to set the DATAEND bit (indicating that no more data is expected).
When the host moves to the status stage of the request, another endpoint 0 interrupt will be generated to
indicate that the request has completed. No further action is required from the software, the interrupt is
just a confirmation that the request completed successfully.
If the command is an unrecognized command, or for some other reason cannot be executed, then when it
has been decoded, the PERI_CSR0 register should be written to set the SERV_RXPKTRDY bit (bit 6) and
to set the SENDSTALL bit (bit 5). When the host sends more data, the controller will send a STALL to tell
the host that the request was not executed. An endpoint 0 interrupt will be generated and the SENTSTALL
bit of PERI_CSR0 (bit 2) will be set.
If the host sends more data after the DATAEND has been set, then the controller will send a STALL. An
endpoint 0 interrupt will be generated and the SENTSTALL bit of PERI_CSR0 (bit 2) will be set.
3.1.1.3
Read Requests
Read requests have a packet (or packets) of data sent from the function to the host after the 8-byte
command. Examples of Read Standard Device Requests are:
• GET_CONFIGURATION
• GET_INTERFACE
• GET_DESCRIPTOR
• GET_STATUS
• SYNCH_FRAME
The sequence of events will begin, as with all requests, when the software receives an endpoint 0
interrupt. The RXPKTRDY bit of PERI_CSR0 (bit 0) will also have been set. The 8-byte command should
then be read from the endpoint 0 FIFO and decoded. The PERI_CSR0 register should then be written to
set the SERV_RXPKTRDY bit (bit 6) (indicating that the command has read from the FIFO).
The data to be sent to the host should then be written to the endpoint 0 FIFO. If the data to be sent is
greater than the maximum packet size for endpoint 0, only the maximum packet size should be written to
the FIFO. The PERI_CSR0 register should then be written to set the TXPKTRDY bit (bit 1) (indicating that
there is a packet in the FIFO to be sent). When the packet has been sent to the host, another endpoint 0
interrupt will be generated and the next data packet can be written to the FIFO.
When the last data packet has been written to the FIFO, the PERI_CSR0 register should be written to set
the TXPKTRDY bit and to set the DATAEND bit (bit 3) (indicating that there is no more data after this
packet).
When the host moves to the status stage of the request, another endpoint 0 interrupt will be generated to
indicate that the request has completed. No further action is required from the software: the interrupt is
just a confirmation that the request completed successfully.
If the command is an unrecognized command, or for some other reason cannot be executed, then when it
has been decoded, the PERI_CSR0 register should be written to set the SERV_RXPKTRDY bit (bit 6) and
to set the SENDSTALL bit (bit 5). When the host requests data, the controller will send a STALL to tell the
host that the request was not executed. An endpoint 0 interrupt will be generated and the SENTSTALL bit
of PERI_CSR0 (bit 2) will be set.
If the host requests more data after DATAEND (bit 3) has been set, then the controller will send a STALL.
An endpoint 0 interrupt will be generated and the SENTSTALL bit of PERI_CSR0 (bit 2) will be set.
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Endpoint 0 States
When the USB controller is operating as a peripheral device, the endpoint 0 control needs three modes –
IDLE, TX and RX – corresponding to the different phases of the control transfer and the states endpoint 0
enters for the different phases of the transfer (described in later sections).
The default mode on power-up or reset should be IDLE. RXPKTRDY bit of PERI_CSR0 (bit 0) becoming
set when endpoint 0 is in IDLE state indicates a new device request. Once the device request is unloaded
from the FIFO, the controller decodes the descriptor to find whether there is a data phase and, if so, the
direction of the data phase of the control transfer (in order to set the FIFO direction).See Figure 3.
Depending on the direction of the data phase, endpoint 0 goes into either TX state or RX state. If there is
no Data phase, endpoint 0 remains in IDLE state to accept the next device request.
The actions that the CPU needs to take at the different phases of the possible transfers (e.g., loading the
FIFO, setting TXPKTRDY) are indicated in Figure 4 .
Note:
The controller changes the FIFO direction, depending on the direction of the data phase
independently of the CPU.
Figure 3. CPU Actions at Transfer Phases
Sequence #3
Idle
Sequence #1
Sequence #2
Tx state
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Universal Serial Bus (USB) Controller
Rx state
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Figure 4. Sequence of Transfer
Idle
Sequence #1
CPU actions
Setup
TX state
Int
Unload device
req. and clear
RxPktRdy
IN data
phase
Int
IN data
phase
Load FIFO
and set
TxPktRdy
Setup
Int
Load FIFO
and set
TxPktRdy
Idle
Sequence #2
Idle
IN data
phase
Int
OUT data
phase
Int
Unload
device req.
and clear
RxPktRdy
CPU actions
OUT data
phase
Unload FIFO
and clear
RxPktRdy
Int
Load FIFO and
set TxPktRdy
and set DataEnd
RX state
Int
Status phase
(OUT)
Idle
Int
OUT data
phase
Unload FIFO
and clear
RxPktRdy
Int
Status phase
(IN)
Int
Unload FIFO and
clear RxPktRdy
and set DataEnd
No data phase
Sequence #3
Setup
Int
Status phase
(IN)
Int
Idle
CPU actions
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Unload device req and
clear RxPktRdy and set
DataEnd
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Endpoint 0 Service Routine
An Endpoint 0 interrupt is generated when:
• The controller sets the RXPKTRDY bit of PERI_CSR0 (bit 0) after a valid token has been received and
data has been written to the FIFO.
• The controller clears the TXPKTRDY bit of PERI_CSR0 (bit 1) after the packet of data in the FIFO has
been successfully transmitted to the host.
• The controller sets the SENTSTALL bit of PERI_CSR0 (bit 2) after a control transaction is ended due
to a protocol violation.
• The controller sets the SETUPEND bit of PERI_CSR0 (bit 4) because a control transfer has ended
before DATAEND (bit 3 of PERI_CSR0) is set.
Whenever the endpoint 0 service routine is entered, the software must first check to see if the current
control transfer has been ended due to either a STALL condition or a premature end of control transfer. If
the control transfer ends due to a STALL condition, the SENTSTALL bit would be set. If the control
transfer ends due to a premature end of control transfer, the SETUPEND bit would be set. In either case,
the software should abort processing the current control transfer and set the state to IDLE.
Once the software has determined that the interrupt was not generated by an illegal bus state, the next
action taken depends on the endpoint state. Figure 5 shows the flow of this process.
If endpoint 0 is in IDLE state, the only valid reason an interrupt can be generated is as a result of the
controller receiving data from the bus. The service routine must check for this by testing the RXPKTRDY
bit of PERI_CSR0 (bit 0). If this bit is set, then the controller has received a SETUP packet. This must be
unloaded from the FIFO and decoded to determine the action the controller must take. Depending on the
command contained within the SETUP packet, endpoint 0 will enter one of three states:
• If the command is a single packet transaction (SET_ADDRESS, SET_INTERFACE etc.) without any
data phase, the endpoint will remain in IDLE state.
• If the command has an OUT data phase (SET_DESCRIPTOR etc.), the endpoint will enter RX state.
• If the command has an IN data phase ( GET_DESCRIPTOR etc.), the endpoint will enter TX state.
If the endpoint 0 is in TX state, the interrupt indicates that the core has received an IN token and data
from the FIFO has been sent. The software must respond to this either by placing more data in the FIFO if
the host is still expecting more data or by setting the DATAEND bit to indicate that the data phase is
complete. Once the data phase of the transaction has been completed, endpoint 0 should be returned to
IDLE state to await the next control transaction.
Note:
All command transactions include a field that indicates the amount of data the host expects
to receive or is going to send.
If the endpoint is in RX state, the interrupt indicates that a data packet has been received. The software
must respond by unloading the received data from the FIFO. The software must then determine whether it
has received all of the expected data. If it has, the software should set the DATAEND bit and return
endpoint 0 to IDLE state. If more data is expected, the firmware should set the SERV_RXPKTRDY bit of
PERI_CSR0 (bit 6) to indicate that it has read the data in the FIFO and leave the endpoint in RX state.
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Figure 5. Service Endpoint 0 Flow Chart
Service
endpoint 0
Read endpoint 0 CSR
Sent
stall
?
Yes
Clear SentStall bit
state −> IDLE
Yes
Set ServicedSetupEnd
state −> IDLE
No
Setup
end
?
No
State
= IDLE
?
Yes
IDLE mode
No
State
= TX
?
Yes
TX mode
No
State
= RX*
?
Yes
RX mode
* By default
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IDLE Mode
IDLE mode is the mode the endpoint 0 control must select at power-on or reset and is the mode to which
the endpoint 0 control should return when the RX and TX modes are terminated. It is also the mode in
which the SETUP phase of control transfer is handled (as outlined in Figure 6).
Figure 6. IDLE Mode Flow Chart
IDLE mode
RxPktRdy
set?
No
Return
Yes
Unload FIFO
Decode command
Command
has data
phase
?
No
Set ServicedRxPktRdy
Set DataEnd
Yes
Set
ServiceRxPktRdy
Data
phase = IN
?
No
Process command
Return
Yes
State −> TX
Return
State −> RX
Return
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3.1.1.5.2
TX Mode
When the endpoint is in TX state all arriving IN tokens need to be treated as part of a data phase until the
required amount of data has been sent to the host. If either a SETUP or an OUT token is received while
the endpoint is in the TX state, this will cause a SetupEnd condition to occur as the core expects only IN
tokens. See Figure 7.
Three events can cause TX mode to be terminated before the expected amount of data has been sent:
1. The host sends an invalid token causing a SETUPEND condition (bit 4 of PERI_CSR0 set).
2. The software sends a packet containing less than the maximum packet size for endpoint 0.
3. The software sends an empty data packet.
Until the transaction is terminated, the software simply needs to load the FIFO when it receives an
interrupt that indicates a packet has been sent from the FIFO. (An interrupt is generated when
TXPKTRDY is cleared.)
When the software forces the termination of a transfer (by sending a short or empty data packet), it should
set the DATAEND bit of PERI_CSR0 (bit 3) to indicate to the core that the data phase is complete and
that the core should next receive an acknowledge packet.
Figure 7. TX Mode Flow Chart
TX mode
Write
MaxP bytes
to FIFO
Last
packet
?
No
Set
TxPktRdy
Yes
Set TxPktRdy
and set DataEnd
state −> IDLE
Return
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RX Mode
In RX mode, all arriving data should be treated as part of a data phase until the expected amount of data
has been received. If either a SETUP or an IN token is received while the endpoint is in RX state, a
SetupEnd condition will occur as the controller expects only OUT tokens.
Three events can cause RX mode to be terminated before the expected amount of data has been
received as shown in Figure 8:
1. The host sends an invalid token causing a SETUPEND condition (setting bit 4 of PERI_CSR0).
2. The host sends a packet which contains less than the maximum packet size for endpoint 0.
3. The host sends an empty data packet.
Until the transaction is terminated, the software unloads the FIFO when it receives an interrupt that
indicates new data has arrived (setting RXPKTRDY bit of PERI_CSR0) and to clear RXPKTRDY by
setting the SERV_RXPKTRDY bit of PERI_CSR0 (bit 6).
When the software detects the termination of a transfer (by receiving either the expected amount of data
or an empty data packet), it should set the DATAEND bit (bit 3 of PERI_CSR0) to indicate to the controller
that the data phase is complete and that the core should receive an acknowledge packet next.
Figure 8. RX Mode Flow Chart
RX mode
RxPktRdy
set
?
No
Return
Yes
Read Count0
register (n)
Unload n bytes
from FIFO
Last
packet
?
No
Set
ServicedRxPktRdy
Yes
Set
ServicedRxPktRdy
and DataEnd
state->IDLE
Return
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3.1.1.5.4
Error Handling
A control transfer may be aborted due to a protocol error on the USB, the host prematurely ending the
transfer, or if the software wishes to abort the transfer (e.g., because it cannot process the command).
The controller automatically detects protocol errors and sends a STALL packet to the host under the
following conditions:
• The host sends more data during the OUT Data phase of a write request than was specified in the
command. This condition is detected when the host sends an OUT token after the DATAEND bit (bit 3
of PERI_CSR0) has been set.
• The host requests more data during the IN Data phase of a read request than was specified in the
command. This condition is detected when the host sends an IN token after the DATAEND bit in the
PERI_CSR0 register has been set.
• The host sends more than Max Packet Size data bytes in an OUT data packet.
• The host sends a non-zero length DATA1 packet during the STATUS phase of a read request.
When the controller has sent the STALL packet, it sets the SENTSTALL bit (bit 2 of PERI_CSR0) and
generates an interrupt. When the software receives an endpoint 0 interrupt with the SENTSTALL bit set, it
should abort the current transfer, clear the SENTSTALL bit, and return to the IDLE state.
If the host prematurely ends a transfer by entering the STATUS phase before all the data for the request
has been transferred, or by sending a new SETUP packet before completing the current transfer, then the
SETUPEND bit (bit 4 of PERI_CSR0) will be set and an endpoint 0 interrupt generated. When the
software receives an endpoint 0 interrupt with the SETUPEND bit set, it should abort the current transfer,
set the SERV_SETUPEND bit (bit 7 of PERI_CSR0), and return to the IDLE state. If the RXPKTRDY bit
(bit 0 of PERI_CSR0) is set this indicates that the host has sent another SETUP packet and the software
should then process this command.
If the software wants to abort the current transfer, because it cannot process the command or has some
other internal error, then it should set the SENDSTALL bit (bit 5 of PERI_CSR0). The controller will then
send a STALL packet to the host, set the SENTSTALL bit (bit 2 of PERI_CSR0) and generate an endpoint
0 interrupt.
3.1.1.5.5
Additional Conditions
When working as a peripheral device, the controller automatically responds to certain conditions on the
USB bus or actions by the host. The details are given below:
• Stall Issued to Control Transfers
– The host sends more data during an OUT Data phase of a Control transfer than was specified in
the device request during the SETUP phase. This condition is detected by the controller when the
host sends an OUT token (instead of an IN token) after the software has unloaded the last OUT
packet and set DataEnd.
– The host requests more data during an IN data phase of a Control transfer than was specified in
the device request during the SETUP phase. This condition is detected by the controller when the
host sends an IN token (instead of an OUT token) after the software has cleared TXPKTRDY and
set DataEnd in response to the ACK issued by the host to what should have been the last packet.
– The host sends more than MaxPktSize data with an OUT data token.
– The host sends the wrong PID for the OUT Status phase of a Control transfer.
– The host sends more than a zero length data packet for the OUT Status phase.
• Zero Length Out Data Packets In Control Transfer
– A zero length OUT data packet is used to indicate the end of a Control transfer. In normal
operation, such packets should only be received after the entire length of the device request has
been transferred (i.e., after the software has set DataEnd). If, however, the host sends a zero
length OUT data packet before the entire length of device request has been transferred, this signals
the premature end of the transfer. In this case, the controller will automatically flush any IN token
loaded by software ready for the Data phase from the FIFO and set SETUPEND bit (bit 4 of
PERI_CSR0).
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Bulk Transactions
3.1.2.1
Bulk In Transactions
A Bulk IN transaction is used to transfer non-periodic data from the USB peripheral device to the host.
The following optional features are available for use with a Tx endpoint used in peripheral mode for Bulk
IN transactions:
• Double packet buffering: When enabled, up to two packets can be stored in the FIFO awaiting
transmission to the host. Double packet buffering is enabled by setting the DPB bit of TXFIFOSZ
register (bit 4).
• DMA: If DMA is enabled for the endpoint, a DMA request will be generated whenever the endpoint is
able to accept another packet in its FIFO. This feature allows the DMA controller to load packets into
the FIFO without processor intervention.
When DMA is enabled and DMAMODE bit of PERI_TXCSR is set, an endpoint interrupt is not
generated for completion of the packet transfer. An endpoint interrupt is generated only in the error
conditions.
3.1.2.1.1
Setup
In configuring a TX endpoint for bulk transactions, the TXMAXP register must be written with the
maximum packet size (in bytes) for the endpoint. This value should be the same as the wMaxPacketSize
field of the Standard Endpoint Descriptor for the endpoint and the PERI_TXCSR register should be set as
shown in Table 2:
Table 2. PERI_TXCSR Register Bit Configuration for Bulk IN Transactions
Bit Position
Bit Field Name
Configuration
Bit 14
ISO
Set to 0 for bulk mode operation
Bit 13
MODE
Set to 1 to make sure the FIFO is enabled (only necessary if the FIFO is shared with an RX
endpoint)
Bit 12
DMAEN
Set to 1 if DMA requests must be enabled
Bit 11
FRCDATATOG
Set to 0 to allow normal data toggle operations
Bit 10
DMAMODE
Set to 1 when DMA is enabled and EP interrupt is not needed for each packet transmission
When the endpoint is first configured (following a SET_CONFIGURATION or SET_INTERFACE command
on Endpoint 0), the lower byte of PERI_TXCSR should be written to set the CLRDATATOG bit (bit 6). This
will ensure that the data toggle (which is handled automatically by the controller) starts in the correct state.
Also if there are any data packets in the FIFO (indicated by the FIFONOTEMPTY bit (bit 1 of
PERI_TXCSR) being set), they should be flushed by setting the FLUSHFIFO bit (bit 3 of PERI_TXCSR).
Note:
38
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3.1.2.1.2
Operation
When data is to be transferred over a Bulk IN pipe, a data packet needs to be loaded into the FIFO and
the PERI_TXCSR register written to set the TXPKTRDY bit (bit 0). When the packet has been sent, the
TXPKTRDY bit will be cleared by the USB controller and an interrupt generated so that the next packet
can be loaded into the FIFO. If double packet buffering is enabled, then after the first packet has been
loaded and the TXPKTRDY bit set, the TXPKTRDY bit will immediately be cleared by the USB controller
and an interrupt generated so that a second packet can be loaded into the FIFO. The software should
operate in the same way, loading a packet when it receives an interrupt, regardless of whether double
packet buffering is enabled or not.
In the general case, the packet size must not exceed the size specified by the lower 11 bits of the
TXMAXP register. This part of the register defines the payload (packet size) for transfers over the USB
and is required by the USB Specification to be either 8, 16, 32, 64 (Full-Speed or High-Speed) or 512
bytes (High-Speed only).
The host may determine that all the data for a transfer has been sent by knowing the total amount of data
that is expected. Alternatively it may infer that all the data has been sent when it receives a packet which
is smaller than the stated payload (TXMAXP [bit 10 : bit 0]). In the latter case, if the total size of the data
block is a multiple of this payload, it will be necessary for the function to send a null packet after all the
data has been sent. This is done by setting TXPKTRDY when the next interrupt is received, without
loading any data into the FIFO.
If large blocks of data are being transferred, then the overhead of calling an interrupt service routine to
load each packet can be avoided by using DMA.
3.1.2.1.3
Error Handling
If the software wants to shut down the Bulk IN pipe, it should set the SENDSTALL bit (bit 4 of
PERI_TXCSR). When the controller receives the next IN token, it will send a STALL to the host, set the
SENTSTALL bit (bit 5 of PERI_TXCSR) and generate an interrupt.
When the software receives an interrupt with the SENTSTALL bit (bit 5 of PERI_TXCSR) set, it should
clear the SENTSTALL bit. It should however leave the SENDSTALL bit set until it is ready to re-enable the
Bulk IN pipe.
Note:
3.1.2.2
If the host failed to receive the STALL packet for some reason, it will send another IN token,
so it is advisable to leave the SENDSTALL bit set until the software is ready to re-enable the
Bulk IN pipe. When a pipe is re-enabled, the data toggle sequence should be restarted by
setting the CLRDATATOG bit in the PERI_TXCSR register (bit 6).
Bulk OUT Transactions
A Bulk OUT transaction is used to transfer non-periodic data from the host to the function controller.
The following optional features are available for use with an Rx endpoint used in peripheral mode for Bulk
OUT transactions:
• Double packet buffering: When enabled, up to two packets can be stored in the FIFO on reception
from the host. Double packet buffering is enabled by setting the DPB bit of the RXFIFOSZ register (bit
4).
• DMA: If DMA is enabled for the endpoint, a DMA request will be generated whenever the endpoint has
a packet in its FIFO. This feature can be used to allow the DMA controller to unload packets from the
FIFO without processor intervention.
When DMA is enabled, endpoint interrupt will not be generated for completion of packet reception.
Endpoint interrupt will be generated only in the error conditions.
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Setup
In configuring an Rx endpoint for Bulk OUT transactions, the RXMAXP register must be written with the
maximum packet size (in bytes) for the endpoint. This value should be the same as the wMaxPacketSize
field of the Standard Endpoint Descriptor for the endpoint. In addition, the relevant interrupt enable bit in
the INTRRXE register should be set (if an interrupt is required for this endpoint) and the PERI_RXCSR
register should be set as shown in Table 3.
Table 3. PERI_RXCSR Register Bit Configuration for Bulk OUT Transactions
Bit Position
Bit Field Name
Configuration
Bit 14
ISO
Set to 0 to enable Bulk protocol
Bit 13
DMAEN
Set to 1 if a DMA request is required for this endpoint
Bit 12
DISNYET
Set to 0 to allow normal PING flow control. This will affect only high speed transactions.
Bit 11
DMAMODE
Always set this bit to 0
When the endpoint is first configured (following a SET_CONFIGURATION or SET_INTERFACE command
on Endpoint 0), the lower byte of PERI_RXCSR should be written to set the CLRDATATOG bit (bit 7).
This will ensure that the data toggle (which is handled automatically by the USB controller) starts in the
correct state.
Also if there are any data packets in the FIFO (indicated by the RXPKTRDY bit (bit 0 of PERI_RXCSR)
being set), they should be flushed by setting the FLUSHFIFO bit (bit 4 of PERI_RXCSR).
Note:
3.1.2.2.2
It may be necessary to set this bit twice in succession if double buffering is enabled.
Operation
When a data packet is received by a Bulk Rx endpoint, the RXPKTRDY bit (bit 0 of PERI_RXCSR) is set
and an interrupt is generated. The software should read the RXCOUNT register for the endpoint to
determine the size of the data packet. The data packet should be read from the FIFO, then the
RXPKTRDY bit should be cleared.
The packets received should not exceed the size specified in the RXMAXP register (as this should be the
value set in the wMaxPacketSize field of the endpoint descriptor sent to the host). When a block of data
larger than wMaxPacketSize needs to be sent to the function, it will be sent as multiple packets. All the
packets will be wMaxPacketSize in size, except the last packet which will contain the residue. The
software may use an application specific method of determining the total size of the block and hence when
the last packet has been received. Alternatively it may infer that the entire block has been received when it
receives a packet which is less than wMaxPacketSize in size. (If the total size of the data block is a
multiple of wMaxPacketSize, a null data packet will be sent after the data to signify that the transfer is
complete.)
In the general case, the application software will need to read each packet from the FIFO individually. If
large blocks of data are being transferred, the overhead of calling an interrupt service routine to unload
each packet can be avoided by using DMA.
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3.1.2.2.3
Error Handling
If the software wants to shut down the Bulk OUT pipe, it should set the SENDSTALL bit (bit 5 of
PERI_RXCSR). When the controller receives the next packet it will send a STALL to the host, set the
SENTSTALL bit (bit 6 of PERI_RXCSR) and generate an interrupt.
When the software receives an interrupt with the SENTSTALL bit (bit 6 of PERI_RXCSR) set, it should
clear this bit. It should however leave the SENDSTALL bit set until it is ready to re-enable the Bulk OUT
pipe.
Note:
3.1.3
If the host failed to receive the STALL packet for some reason, it will send another packet, so
it is advisable to leave the SENDSTALL bit set until the software is ready to re-enable the
Bulk OUT pipe. When a Bulk OUT pipe is re-enabled, the data toggle sequence should be
restarted by setting the CLRDATATOG bit (bit 7) in the PERI_RXCSR register.
Interrupt Transactions
An Interrupt IN transaction uses the same protocol as a Bulk IN transaction and can be used the same
way. Similarly, an Interrupt OUT transaction uses almost the same protocol as a Bulk OUT transaction
and can be used the same way.
Tx endpoints in the USB controller have one feature for Interrupt IN transactions that they do not support
in Bulk IN transactions. In Interrupt IN transactions, the endpoints support continuous toggle of the data
toggle bit.
This feature is enabled by setting the FRCDATATOG bit in the PERI_TXCSR register (bit 11). When this
bit is set, the controller will consider the packet as having been successfully sent and toggle the data bit
for the endpoint, regardless of whether an ACK was received from the host.
Another difference is that interrupt endpoints do not support PING flow control. This means that the
controller should never respond with a NYET handshake, only ACK/NAK/STALL. To ensure this, the
DISNYET bit in the PERI_RXCSR register (bit 12) should be set to disable the transmission of NYET
handshakes in high-speed mode.
Though DMA can be used with an interrupt OUT endpoint, it generally offers little benefit as interrupt
endpoints are usually expected to transfer all their data in a single packet.
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Isochronous Transactions
3.1.4.1
Isochronous IN Transactions
An Isochronous IN transaction is used to transfer periodic data from the function controller to the host.
The following optional features are available for use with a Tx endpoint used in Peripheral mode for
Isochronous IN transactions:
• Double packet buffering: When enabled, up to two packets can be stored in the FIFO awaiting
transmission to the host. Double packet buffering is enabled by setting the DPB bit of TXFIFOSZ
register (bit 4).
Note:
•
Double packet buffering is generally advisable for Isochronous transactions in order to avoid
Underrun errors as described in later section.
DMA: If DMA is enabled for the endpoint, a DMA request will be generated whenever the endpoint is
able to accept another packet in its FIFO. This feature allows the DMA controller to load packets into
the FIFO without processor intervention.
However, this feature is not particularly useful with Isochronous endpoints because the packets
transferred are often not maximum packet size and the PERI_TXCSR register needs to be accessed
following every packet to check for Underrun errors.
When DMA is enabled and DMAMODE bit of PERI_TXCSR is set, endpoint interrupt will not be
generated for completion of packet transfer. Endpoint interrupt will be generated only in the error
conditions.
3.1.4.1.1
Setup
In configuring a Tx endpoint for Isochronous IN transactions, the TXMAXP register must be written with
the maximum packet size (in bytes) for the endpoint. This value should be the same as the
wMaxPacketSize field of the Standard Endpoint Descriptor for the endpoint. In addition, the relevant
interrupt enable bit in the INTRTXE register should be set (if an interrupt is required for this endpoint) and
the PERI_TXCSR register should be set as shown in Table 4.
Table 4. PERI_TXCSR Register Bit Configuration for Isochronous IN Transactions
Bit Position
Bit Field Name
Configuration
Bit 14
ISO
Set to 1 to enable Isochronous transfer protocol
Bit 13
MODE
Set to 1 to ensure the FIFO is enabled (only necessary if the FIFO is shared with an Rx
endpoint).
Bit 12
DMAEN
Set to 1 if DMA Requests have to be enabled
Bit 11
FRCDATATOG
Ignored in Isochronous mode
Bit 10
DMAMODE
Set it to 1, when DMA is enabled and EP interrupt is not needed for each packet
transmission
3.1.4.1.2
Operation
An Isochronous endpoint does not support data retries, so if data underrun is to be avoided, the data to be
sent to the host must be loaded into the FIFO before the IN token is received. The host will send one IN
token per frame (or microframe in High-speed mode), however the timing within the frame (or microframe)
can vary. If an IN token is received near the end of one frame and then at the start of the next frame,
there will be little time to reload the FIFO. For this reason, double buffering of the endpoint is usually
necessary.
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An interrupt is generated whenever a packet is sent to the host and the software may use this interrupt to
load the next packet into the FIFO and set the TXPKTRDY bit in the PERI_TXCSR register (bit 0) in the
same way as for a Bulk Tx endpoint. As the interrupt could occur almost any time within a
frame(/microframe), depending on when the host has scheduled the transaction, this may result in
irregular timing of FIFO load requests. If the data source for the endpoint is coming from some external
hardware, it may be more convenient to wait until the end of each frame(/microframe) before loading the
FIFO as this will minimize the requirement for additional buffering. This can be done by using either the
SOF interrupt or the external SOF_PULSE signal from the controller to trigger the loading of the next data
packet. The SOF_PULSE is generated once per frame(/microframe) when a SOF packet is received. (The
controller also maintains an external frame(/microframe) counter so it can still generate a SOF_PULSE
when the SOF packet has been lost.) The interrupts may still be used to set the TXPKTRDY bit in
PERI_TXCSR (bit 0) and to check for data overruns/underruns.
Starting up a double-buffered Isochronous IN pipe can be a source of problems. Double buffering requires
that a data packet is not transmitted until the frame(/microframe) after it is loaded. There is no problem if
the function loads the first data packet at least a frame(/microframe) before the host sets up the pipe (and
therefore starts sending IN tokens). But if the host has already started sending IN tokens by the time the
first packet is loaded, the packet may be transmitted in the same frame(/microframe) as it is loaded,
depending on whether it is loaded before, or after, the IN token is received. This potential problem can be
avoided by setting the ISOUPDATE bit in the POWER register (bit 7). When this bit is set, any data packet
loaded into an Isochronous Tx endpoint FIFO will not be transmitted until after the next SOF packet has
been received, thereby ensuring that the data packet is not sent too early.
3.1.4.1.3
Error Handling
If the endpoint has no data in its FIFO when an IN token is received, it will send a null data packet to the
host and set the UNDERRUN bit in the PERI_TXCSR register (bit 2). This is an indication that the
software is not supplying data fast enough for the host. It is up to the application to determine how this
error condition is handled.
If the software is loading one packet per frame(/microframe) and it finds that the TXPKTRDY bit in the
PERI_TXCSR register (bit 0) is set when it wants to load the next packet, this indicates that a data packet
has not been sent (perhaps because an IN token from the host was corrupted). It is up to the application
how it handles this condition: it may choose to flush the unsent packet by setting the FLUSHFIFO bit in
the PERI_TXCSR register (bit 3), or it may choose to skip the current packet.
3.1.4.2
Isochronous OUT Transactions
An Isochronous OUT transaction is used to transfer periodic data from the host to the function controller.
Following optional features are available for use with an Rx endpoint used in Peripheral mode for
Isochronous OUT transactions:
• Double packet buffering: When enabled, up to two packets can be stored in the FIFO on reception
from the host. Double packet buffering is enabled by setting the DPB bit of RXFIFOSZ register (bit 4).
Note:
•
Double packet buffering is generally advisable for Isochronous transactions in order to avoid
Overrun errors.
DMA: If DMA is enabled for the endpoint, a DMA request will be generated whenever the endpoint has
a packet in its FIFO. This feature can be used to allow the DMA controller to unload packets from the
FIFO without processor intervention.
However, this feature is not particularly useful with Isochronous endpoints because the packets
transferred are often not maximum packet size and the PERI_RXCSR register needs to be accessed
following every packet to check for Overrun or CRC errors.
When DMA is enabled, endpoint interrupt will not be generated for completion of packet reception.
Endpoint interrupt will be generated only in the error conditions.
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Setup
In configuring an Rx endpoint for Isochronous OUT transactions, the RXMAXP register must be written
with the maximum packet size (in bytes) for the endpoint. This value should be the same as the
wMaxPacketSize field of the Standard Endpoint Descriptor for the endpoint. In addition, the relevant
interrupt enable bit in the INTRRXE register should be set (if an interrupt is required for this endpoint) and
the PERI_RXCSR register should be set as shown in Table 5.
Table 5. PERI_RXCSR Register Bit Configuration for Isochronous OUT Transactions
Bit Position
Bit Field Name
Configuration
Bit 14
ISO
Set to 1 to enable isochronous protocol
Bit 13
DMAEN
Set to 1 if a DMA request is required for this endpoint
Bit 12
DISNYET
Ignored in isochronous transfers
Bit 11
DMAMODE
Always set this bit to 0
3.1.4.2.2
Operation
An Isochronous endpoint does not support data retries so, if a data overrun is to be avoided, there must
be space in the FIFO to accept a packet when it is received. The host will send one packet per frame (or
microframe in High-speed mode); however, the time within the frame can vary. If a packet is received near
the end of one frame(/microframe) and another arrives at the start of the next frame, there will be little time
to unload the FIFO. For this reason, double buffering of the endpoint is usually necessary.
An interrupt is generated whenever a packet is received from the host and the software may use this
interrupt to unload the packet from the FIFO and clear the RXPKTRDY bit in the PERI_RXCSR register
(bit 0) in the same way as for a Bulk Rx endpoint. As the interrupt could occur almost any time within a
frame(/microframe), depending on when the host has scheduled the transaction, the timing of FIFO unload
requests will probably be irregular. If the data sink for the endpoint is going to some external hardware, it
may be better to minimize the requirement for additional buffering by waiting until the end of each
frame(/microframe) before unloading the FIFO. This can be done by using either the SOF interrupt or the
external SOF_PULSE signal from the controller to trigger the unloading of the data packet. The
SOF_PULSE is generated once per frame(/microframe) when a SOF packet is received. (The controller
also maintains an external frame(/microframe) counter so it can still generate a SOF_PULSE when the
SOF packet has been lost.) The interrupts may still be used to clear the RXPKTRDY bit in PERI_RXCSR
and to check for data overruns/underruns.
3.1.4.2.3
Error Handling
If there is no space in the FIFO to store a packet when it is received from the host, the OVERRUN bit in
the PERI_RXCSR register (bit 2) will be set. This is an indication that the software is not unloading data
fast enough for the host. It is up to the application to determine how this error condition is handled.
If the controller finds that a received packet has a CRC error, it will still store the packet in the FIFO and
set the RXPKTRDY bit (bit 0 of PERI_RXCSR) and the DATAERROR bit (bit 3 of PERI_RXCSR). It is left
up to the application how this error condition is handled.
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3.2
USB Controller Host Mode Operation
•
•
•
•
3.2.1
Entry into Suspend mode. When operating as a host, the controller can be prompted to enter Suspend
mode by setting the SUSPENDM bit in the POWER register. When this bit is set, the controller will
complete the current transaction then stop the transaction scheduler and frame counter. No further
transactions will be started and no SOF packets will be generated. If the ENSUSPM bit (bit 0 of
POWER register) is set, PHY will go into low-power mode when the controller enters Suspend mode.
Sending Resume Signaling. When the application requires the controller to leave Suspend mode, it
must clear the SUSPENDM bit in the POWER register (bit 1), set the RESUME bit (bit 2) and leave it
set for 20ms. While the RESUME bit is high, the controller will generate Resume signaling on the bus.
After 20 ms, the application should clear the Resume bit, at which point the frame counter and
transaction scheduler will be started.
Responding to Remote Wake-up. If Resume signaling is detected from the target while the controller is
in Suspend mode, the PHY will be brought out of low-power mode. The controller will then exit
Suspend mode and automatically set the RESUME bit in the POWER register (bit 2) to take over
generating the Resume signaling from the target. If the Resume interrupt is enabled, an interrupt will
be generated.
Reset Signaling. If the RESET bit in the POWER register (bit 3) is set while the controller is in Host
mode, it will generate Reset signaling on the bus. If the HSENAB bit in the POWER register (bit 5) was
set, it will also try to negotiate for high-speed operation. The software should keep the RESET bit set
for at least 20 ms to ensure correct resetting of the target device. After the software has cleared the bit,
the controller will start its frame counter and transaction scheduler. Whether high-speed operation is
selected will be indicated by HSMODE bit of POWER register (bit 4).
Control Transactions
Host Control Transactions are conducted through Endpoint 0 and the software is required to handle all the
Standard Device Requests that may be sent or received via Endpoint 0 (as described in Universal Serial
Bus Specification, Revision 2.0, Chapter 9).
As for a USB peripheral device, there are three categories of Standard Device Requests to be handled:
Zero Data Requests (in which all the information is included in the command), Write Requests (in which
the command will be followed by additional data), and Read Requests (in which the device is required to
send data back to the host).
1. Zero Data Requests consist of a SETUP command followed by an IN Status Phase
2. Write Requests consist of a SETUP command, followed by an OUT Data Phase which is in turn
followed by an IN Status Phase
3. Read Requests consist of a SETUP command, followed by an IN Data Phase which is in turn followed
by an OUT Status Phase
A timeout may be set to limit the length of time for which the controller will retry a transaction which is
continually NAKed by the target. This limit can be between 2 and 215 frames/ microframes and is set
through the HOST_NAKLIMIT0 register. The following sections describe the CPU actions required for
these different types of requests by examining the steps to take in the different Control Transaction
phases.
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Setup Phase
For the SETUP Phase of a control transaction (Figure 9), the software driving the US host device needs
to:
1. Load the 8 bytes of the required Device request command into the Endpoint 0 FIFO.
2. Set SETUPPKT and TXPKTRDY (bits 3 and 1 of HOST_CSR0, respectively).
Note:
These bits must be set together.
The controller then proceeds to send a SETUP token followed by the 8-byte command to Endpoint 0 of
the addressed device, retrying as necessary. (On errors, controller retries the transaction three times.)
Figure 9. Setup Phase of a Control Transaction Flow Chart
Transaction
scheduled
TxPktRdy
and SetupPkt
both set
?
No
Yes
SETUP token sent
DATA0 oacket sent
Stall
received
?
Yes
RxStall set
TxPktRdy cleared
Error Count cleared
interrupt generated
Command not
supported by
target
No
ACK
received
?
Yes
TxPktRdy cleared
Error Count cleared
Interrupt generated
No
No
NAK limit
reached
?
Yes
Error count
cleared
Transaction
complete
NAK
received
?
No
Yes
Error count
incremented
NAK Timeout set
Endpoint halted
Interrupt generated
No
Error
count=3
?
Yes
Error bit set
TxPktRdy cleared
Error Count cleared
interrupt generated
Implies problem
at peripheral end
of connection.
Transaction deemed
complete
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3. At the end of the attempt to send the data, the controller will generate an Endpoint 0 interrupt. The
software should then read HOST_CSR0 to establish whether the RXSTALL bit (bit 2), the ERROR bit
(bit 4) or the NAK_TIMEOUT bit (bit 7) has been set.
If RXSTALL is set, it indicates that the target did not accept the command (e.g., because it is not
supported by the target device) and so has issued a STALL response.
If ERROR is set, it means that the controller has tried to send the SETUP Packet and the following
data packet three times without getting any response.
If NAK_TIMEOUT is set, it means that the controller has received a NAK response to each attempt to
send the SETUP packet, for longer than the time set in HOST_NAKLIMIT0. The controller can then be
directed either to continue trying this transaction (until it times out again) by clearing the
NAK_TIMEOUT bit or to abort the transaction by flushing the FIFO before clearing the NAK_TIMEOUT
bit.
4. If none of RXSTALL, ERROR or NAK_TIMEOUT is set, the SETUP Phase has been correctly ACKed
and the software should proceed to the following IN Data Phase, OUT Data Phase or IN Status Phase
specified for the particular Standard Device Request.
3.2.1.2
IN Data Phase
For the IN Data Phase of a control transaction (Figure 10), the software driving the USB host device
needs to:
1. Set REQPKT bit of HOST_CSR0 (bit 5).
2. Wait while the controller sends the IN token and receives the required data back.
3. When the controller generates the Endpoint 0 interrupt, read HOST_CSR0 to establish whether the
RXSTALL bit (bit 2), the ERROR bit (bit 4), the NAK_TIMEOUT bit (bit 7) or RXPKTRDY bit (bit 0) has
been set.
If RXSTALL is set, it indicates that the target has issued a STALL response.
If ERROR is set, it means that the controller has tried to send the required IN token three times without
getting any response.
If NAK_TIMEOUT bit is set, it means that the controller has received a NAK response to each attempt
to send the IN token, for longer than the time set in HOST_NAKLIMIT0. The controller can then be
directed either to continue trying this transaction (until it times out again) by clearing the
NAK_TIMEOUT bit or to abort the transaction by clearing REQPKT before clearing the NAK_TIMEOUT
bit.
4. If RXPKTRDY has been set, the software should read the data from the Endpoint 0 FIFO, then clear
RXPKTRDY.
5. If further data is expected, the software should repeat Steps 1 - 4.
When all the data has been successfully received, the CPU should proceed to the OUT Status Phase of
the Control Transaction.
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Figure 10. IN Data Phase Flow Chart
For each IN packet
requested in SETUP phase
ReqPkt
set
?
No
Yes
IN token sent
STALL
received
?
Yes
RxStall set
ReqPkt cleared
Error Count cleared
Interrupt generated
Problem in
data sent
No
No
NAK limit
reached
?
Yes
Error count
cleared
NAK
received
?
No
Yes
NAK Timeout set
Endpoint halted
Interrupt generated
Data0/1
received
?
Yes
ACK sent
RxPktRdy
set
ReqPkt cleared
Error Count cleared
Interrupt generated
No
Error count
incremented
No
Error
count=3
?
Transaction
complete
Yes
Error bit set
ReqPkt cleared
Error Count cleared
Interrupt generated
Implies problem
at peripheral end
of connection.
Transaction deemed
complete
3.2.1.3
OUT Data Phase
For the OUT Data Phase of a control transaction (Figure 11), the software driving the USB host device
needs to:
1. Load the data to be sent into the endpoint 0 FIFO.
2. Set the TXPKTRDY bit of HOST_CSR0 (bit 1). The controller then proceeds to send an OUT token
followed by the data from the FIFO to Endpoint 0 of the addressed device, retrying as necessary.
3. At the end of the attempt to send the data, the controller will generate an Endpoint 0 interrupt. The
software should then read HOST_CSR0 to establish whether the RXSTALL bit (bit 2), the ERROR bit
(bit 4) or the NAK_TIMEOUT bit (bit 7) has been set.
If RXSTALL bit is set, it indicates that the target has issued a STALL response.
If ERROR bit is set, it means that the controller has tried to send the OUT token and the following data
packet three times without getting any response.
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If NAK_TIMEOUT is set, it means that the controller has received a NAK response to each attempt to
send the OUT token, for longer than the time set in the HOST_NAKLIMIT0 register. The controller can
then be directed either to continue trying this transaction (until it times out again) by clearing the
NAK_TIMEOUT bit or to abort the transaction by flushing the FIFO before clearing the NAK_TIMEOUT
bit.
If none of RXSTALL, ERROR or NAKLIMIT is set, the OUT data has been correctly ACKed.
4. If further data needs to be sent, the software should repeat Steps 1 - 3.
When all the data has been successfully sent, the software should proceed to the IN Status Phase of
the Control Transaction.
Figure 11. OUT Data Phase Flow Chart
For each OUT packet
specified in SETUP phase
TxPktRdy
set
?
No
Yes
OUT token sent
DATA0/1 packet sent
Stall
received
?
Yes
RxStall set
TxPktRdy cleared
Error Count cleared
interrupt generated
Command could
not be completed
No
ACK
received
?
Yes
TxPktRdy cleared
Error Count cleared
Interrupt generated
No
No
NAK limit
reached
?
Yes
Error count
cleared
Transaction
complete
NAK
received
?
No
Yes
Error count
incremented
NAK Timeout set
Endpoint halted
Interrupt generated
No
Error
count=3
?
Yes
Error bit set
TxPktRdy cleared
Error Count cleared
interrupt generated
Implies problem
at peripheral end
of connection.
Transaction deemed
complete
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IN Status Phase (following SETUP Phase or OUT Data Phase)
For the IN Status Phase of a Control Transaction (Figure 12), the software driving the USB Host device
needs to:
1. Set the STATUSPKT and REQPKT bits of HOST_CSR0 (bit 6 and bit 5, respectively).
2. Wait while the controller sends an IN token and receives a response from the USB peripheral device.
Figure 12. Completion of SETUP or OUT Data Phase Flow Chart
Completion of either SETUP
phase or OUT data phase
ReqPkt
and StatusPkt
both set
?
No
Yes
IN token sent
STALL
received
?
Yes
RxStall set
ReqPkt cleared
Error Count cleared
Interrupt generated
Command could
not be completed
No
No
NAK limit
reached
?
Yes
Error count
cleared
NAK
received
?
No
Yes
NAK Timeout set
Endpoint halted
Interrupt generated
Data1
received
?
Yes
ACK sent
RxPktRdy
set
ReqPkt cleared
Error Count cleared
Interrupt generated
No
Error count
incremented
No
Error
count=3
?
Transaction
complete
Yes
Error bit set
ReqPkt cleared
Error Count cleared
Interrupt generated
Implies problem
at peripheral end
of connection.
Transaction deemed
complete
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3. When the controller generates the Endpoint 0 interrupt, read HOST_CSR0 to establish whether the
RXSTALL bit (bit 2), the ERROR bit (bit 4), the NAK_TIMEOUT bit (bit 7) or RXPKTRDY bit (bit 0) has
been set.
If RXSTALL bit is set, it indicates that the target could not complete the command and so has issued a
STALL response.
If ERROR bit is set, it means that the controller has tried to send the required IN token three times
without getting any response.
If NAK_TIMEOUT bit is set, it means that the controller has received a NAK response to each attempt
to send the IN token, for longer than the time set in the HOST_NAKLIMIT0 register. The controller can
then be directed either to continue trying this transaction (until it times out again) by clearing the
NAK_TIMEOUT bit or to abort the transaction by clearing REQPKT bit and STATUSPKT bit before
clearing the NAK_TIMEOUT bit.
4. If RxPktRdy has been set, the CPU should simply clear RxPktRdy.
3.2.1.5
OUT Status Phase (following IN Data Phase)
For the OUT Status Phase of a control transaction (Figure 13), the CPU driving the host device needs to:
1. Set STATUSPKT and TXPKTRDY bits of HOST_CSR0 (bit 6 and bit 1, respectively).
Note:
These bits need to be set together.
2. Wait while the controller sends the OUT token and a zero-length DATA1 packet.
3. At the end of the attempt to send the data, the controller will generate an Endpoint 0 interrupt. The
software should then read HOST_CSR0 to establish whether the RXSTALL bit (bit 2), the ERROR bit
(bit 4) or the NAK_TIMEOUT bit (bit 7) has been set.
If RXSTALL bit is set, it indicates that the target could not complete the command and so has issued a
STALL response.
If ERROR bit is set, it means that the controller has tried to send the STATUS Packet and the following
data packet three times without getting any response.
If NAK_TIMEOUT bit is set, it means that the controller has received a NAK response to each attempt
to send the IN token, for longer than the time set in the HOST_NAKLIMIT0 register. The controller can
then be directed either to continue trying this transaction (until it times out again) by clearing the
NAK_TIMEOUT bit or to abort the transaction by flushing the FIFO before clearing the NAK_TIMEOUT
bit.
4. If none of RXSTALL, ERROR or NAK_TIMEOUT bits is set, the STATUS Phase has been correctly
ACKed.
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Figure 13. Completion of IN Data Phase Flow Chart
Completion of
IN data phase
TxPktRdy
and StatusPkt
both set
?
No
Yes
OUT token sent
Zero−length
DATA1 packet sent
Stall
received
?
Yes
RxStall set
TxPktRdy cleared
Error Count cleared
interrupt generated
Command could
not be completed
No
ACK
received
?
Yes
TxPktRdy cleared
Error Count cleared
Interrupt generated
No
No
NAK limit
reached
?
Yes
Error count
cleared
Transaction
complete
NAK
received
?
No
Yes
Error count
incremented
NAK Timeout set
Endpoint halted
Interrupt generated
No
Error
count=3
?
Yes
Error bit set
TxPktRdy cleared
Error Count cleared
interrupt generated
Implies problem
at peripheral end
of connection.
Transaction deemed
complete
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3.2.2
Bulk Transactions
3.2.2.1
Bulk IN Transactions
A Bulk IN transaction may be used to transfer non-periodic data from the external USB peripheral to the
host.
The following optional features are available for use with an Rx endpoint used in host mode to receive the
data:
• Double packet buffering: When enabled, up to two packets can be stored in the FIFO on reception
from the host. This allows that one packet can be received while another is being read. Double packet
buffering is enabled by setting the DPB bit of RXFIFOSZ register (bit 4).
• DMA: If DMA is enabled for the endpoint, a DMA request will be generated whenever the endpoint has
a packet in its FIFO. This feature can be used to allow the DMA controller to unload packets from the
FIFO without processor intervention.
When DMA is enabled, endpoint interrupt will not be generated for completion of packet reception.
Endpoint interrupt will be generated only in the error conditions.
• AutoRequest: When the AutoRequest feature is enabled, the REQPKT bit of HOST_RXCSR (bit 5) will
be automatically set when the RXPKTRDY bit is cleared.
This feature is applicable only when DMA is enabled. To enable AutoRequest feature, set the
AUTOREQ register for the DMA channel associated for the endpoint.
3.2.2.1.1
Setup
Before initiating any Bulk IN Transactions in Host mode:
• The target function address needs to be set in the RXFUNCADDR register for the selected controller
endpoint. (RXFUNCADDR register is available for all endpoints from EP0 to EP4.)
• The HOST_RXTYPE register for the endpoint that is to be used needs to be programmed as follows:
– Operating speed in the SPEED bit field (bits 7 and 6).
– Set 10 (binary value) in the PROT field for bulk transfer.
– Endpoint Number of the target device in RENDPN field. This is the endpoint number contained in
the Rx endpoint descriptor returned by the target device during enumeration.
• The RXMAXP register for the controller endpoint must be written with the maximum packet size (in
bytes) for the transfer. This value should be the same as the wMaxPacketSize field of the Standard
Endpoint Descriptor for the target endpoint.
• The HOST_RXINTERVAL register needs to be written with the required value for the NAK limit (2 - 215
frames/microframes), or set to zero if the NAK timeout feature is not required.
• The relevant interrupt enable bit in the INTRRXE register should be set (if an interrupt is required for
this endpoint).
• The following bits of HOST_RXCSR register should be set as shown below:
– Set DMAEN (bit 13) to 1 if a DMA request is required for this endpoint.
– Clear DSINYET (bit 12) to 0 to allow normal PING flow control. This will affect only High Speed
transactions.
– Always clear DMAMODE (bit 11) to 0.
• If DMA is enabled, the AUTOREQ register can be set for generating IN tokens automatically after
receiving the data. Set the bit field RXn_AUTOREQ (where n is the endpoint number) with binary value
01 or 11.
When the endpoint is first configured, the endpoint data toggle should be set to 0 either by using the
DATATOGWREN and DATATOG bits of HOST_RXCSR (bit 10 and bit 9) to toggle the current setting or
by setting the CLRDATATOG bit of HOST_RXCSR (bit 7). This will ensure that the data toggle (which is
handled automatically by the controller) starts in the correct state. Also if there are any data packets in the
FIFO (indicated by the RXPKTRDY bit (bit 0 of HOST_RXCSR) being set), they should be flushed by
setting the FLUSHFIFO bit of HOST_RXCSR (bit 4).
Note:
It may be necessary to set this bit twice in succession if double buffering is enabled.
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Operation
When Bulk data is required from the USB peripheral device, the software should set the REQPKT bit in
the corresponding HOST_RXCSR register (bit 5). The controller will then send an IN token to the selected
peripheral endpoint and waits for data to be returned.
If data is correctly received, RXPKTRDY bit of HOST_RXCSR (bit 0) is set. If the USB peripheral device
responds with a STALL, RXSTALL bit (bit 6 of HOST_RXCSR) is set. If a NAK is received, the controller
tries again and continues to try until either the transaction is successful or the POLINTVL_NAKLIMIT set
in the HOST_RXINTERVAL register is reached. If no response at all is received, two further attempts are
made before the controller reports an error by setting the ERROR bit of HOST_RXCSR (bit 2).
The controller then generates the appropriate endpoint interrupt, whereupon the software should read the
corresponding HOST_RXCSR register to determine whether the RXPKTRDY, RXSTALL, ERROR or
DATAERR_NAKTIMEOUT bit is set and act accordingly. If the DATAERR_NAKTIMEOUT bit is set, the
controller can be directed either to continue trying this transaction (until it times out again) by clearing the
DATAERR_NAKTIMEOUT bit or to abort the transaction by clearing REQPKT bit before clearing the
DATAERR_NAKTIMEOUT bit.
The packets received should not exceed the size specified in the RXMAXP register (as this should be the
value set in the wMaxPacketSize field of the endpoint descriptor sent to the host).
In the general case, the application software will need to read each packet from the FIFO individually. If
large blocks of data are being transferred, the overhead of calling an interrupt service routine to unload
each packet can be avoided by using DMA.
3.2.2.1.3
Error Handling
If the target wants to shut down the Bulk IN pipe, it will send a STALL response to the IN token. This will
result in the RXSTALL bit of HOST_RXCSR (bit 6) being set.
3.2.2.2
Bulk OUT Transactions
A Bulk OUT transaction may be used to transfer non-periodic data from the host to the USB peripheral.
Following optional features are available for use with a Tx endpoint used in Host mode to transmit this
data:
• Double packet buffering: When enabled, up to two packets can be stored in the FIFO awaiting
transmission to the peripheral device. Double packet buffering is enabled by setting the DPB bit of
TXFIFOSZ register (bit 4).
• DMA: If DMA is enabled for the endpoint, a DMA request will be generated whenever the endpoint is
able to accept another packet in its FIFO. This feature can be used to allow the DMA controller to load
packets into the FIFO without processor intervention.
When DMA is enabled and DMAMODE bit in HOST_TXCSR register is set, an endpoint interrupt will
not be generated for completion of packet reception. An endpoint interrupt will be generated only in the
error conditions.
3.2.2.2.1
Setup
Before initiating any bulk OUT transactions:
• The target function address needs to be set in the TXFUNCADDR register for the selected controller
endpoint. (TXFUNCADDR register is available for all endpoints from EP0 to EP4.)
• The HOST_TXTYPE register for the endpoint that is to be used needs to be programmed as follows:
– Operating speed in the SPEED bit field (bits 7 and 6).
– Set 10b in the PROT field for bulk transfer.
– Endpoint Number of the target device in TENDPN field. This is the endpoint number contained in
the OUT(Tx) endpoint descriptor returned by the target device during enumeration.
• The TXMAXP register for the controller endpoint must be written with the maximum packet size (in
bytes) for the transfer. This value should be the same as the wMaxPacketSize field of the Standard
Endpoint Descriptor for the target endpoint.
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•
•
•
The HOST_TXINTERVAL register needs to be written with the required value for the NAK limit (2 - 215
frames/microframes), or set to zero if the NAK timeout feature is not required.
The relevant interrupt enable bit in the INTRTXE register should be set (if an interrupt is required for
this endpoint).
The following bits of HOST_TXCSR register should be set as shown below:
– Set the MODE bit (bit 13) to 1 to ensure the FIFO is enabled (only necessary if the FIFO is shared
with an Rx endpoint).
– Set the DMAEN bit (bit 12) to 1 if a DMA request is required for this endpoint.
– Clear the FRCDATATOG bit (bit 11) to 0 to allow normal data toggle operations.
– Set the DMAMODE bit (bit 10) to 1 when DMA is enabled and the endpoint interrupt is not needed
for each packet transmission.
When the endpoint is first configured, the endpoint data toggle should be set to 0 either by using the
DATATOGWREN bit and DATATOG bit of HOST_TXCSR (bit 9 and bit 8) to toggle the current setting or
by setting the CLRDATATOG bit of HOST_TXCSR (bit 6). This will ensure that the data toggle (which is
handled automatically by the controller) starts in the correct state. Also, if there are any data packets in
the FIFO (indicated by the FIFONOTEMPTY bit of HOST_TXCSR register (bit 1) being set), they should
be flushed by setting the FLUSHFIFO bit (bit 3 of HOST_TXCSR).
Note:
3.2.2.2.2
It may be necessary to set this bit twice in succession if double buffering is enabled.
Operation
When Bulk data is required to be sent to the USB peripheral device, the software should write the first
packet of the data to the FIFO (or two packets if double-buffered) and set the TXPKTRDY bit in the
corresponding HOST_TXCSR register (bit 0). The controller will then send an OUT token to the selected
peripheral endpoint, followed by the first data packet from the FIFO.
If data is correctly received by the peripheral device, an ACK should be received whereupon the controller
will clear TXPKTRDY bit of HOST_TXCSR (bit 0). If the USB peripheral device responds with a STALL,
the RXSTALL bit (bit 5) of HOST_TXCSR is set. If a NAK is received, the controller tries again and
continues to try until either the transaction is successful or the NAK limit set in the HOST_TXINTERVAL
register is reached. If no response at all is received, two further attempts are made before the controller
reports an error by setting ERROR bit in HOST_TXCSR (bit 2).
The controller then generates the appropriate endpoint interrupt, whereupon the software should read the
corresponding HOST_TXCSR register to determine whether the RXSTALL (bit 5), ERROR (bit 2) or
NAK_TIMEOUT (bit 7) bit is set and act accordingly. If the NAK_TIMEOUT bit is set, the controller can be
directed either to continue trying this transaction (until it times out again) by clearing the NAK_TIMEOUT
bit or to abort the transaction by flushing the FIFO before clearing the NAK_TIMEOUT bit.
If large blocks of data are being transferred, then the overhead of calling an interrupt service routine to
load each packet can be avoided by using DMA.
3.2.2.2.3
Error Handling
If the target wants to shut down the Bulk OUT pipe, it will send a STALL response. This is indicated by the
RXSTALL bit of HOST_TXCSR register (bit 5) being set.
3.2.3
Interrupt Transactions
When the controller is operating as the host, interactions with an Interrupt endpoint on the USB peripheral
device are handled in very much the same way as the equivalent Bulk transactions (described in previous
sections).
The principal difference as far as operational steps are concerned is that PROT field of HOST_RXTYPE
and HOST_TXTYPE (bits 5:4) need to be set (binary value) to represent an Interrupt transaction.
The required polling interval also needs to be set in the HOST_RXINTERVAL and HOST_TXINTERVAL
registers.
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Isochronous Transactions
3.2.4.1
Isochronous IN Transactions
An Isochronous IN transaction is used to transfer periodic data from the USB peripheral to the host.
The following optional features are available for use with an Rx endpoint used in Host mode to receive this
data:
• Double packet buffering: When enabled, up to two packets can be stored in the FIFO on reception
from the host. This allows that one packet can be received while another is being read. Double packet
buffering is enabled by setting the DPB bit of RXFIFOSZ register (bit 4).
• DMA: If DMA is enabled for the endpoint, a DMA request will be generated whenever the endpoint has
a packet in its FIFO. This feature can be used to allow the DMA controller to unload packets from the
FIFO without processor intervention. However, this feature is not particularly useful with isochronous
endpoints because the packets transferred are often not maximum packet size.
When DMA is enabled, endpoint interrupt will not be generated for completion of packet reception.
Endpoint interrupt will be generated only in the error conditions.
• AutoRequest: When the AutoRequest feature is enabled, the REQPKT bit of HOST_RXCSR (bit 5) will
be automatically set when the RXPKTRDY bit is cleared.
This feature is applicable only when DMA is enabled. To enable AutoRequest feature, set the
AUTOREQ register for the DMA channel associated for the endpoint.
3.2.4.1.1
Setup
Before initiating an Isochronous IN Transactions in Host mode:
• The target function address needs to be set in the RXFUNCADDR register for the selected controller
endpoint (RXFUNCADDR register is available for all endpoints from EP0 to EP4).
• The HOST_RXTYPE register for the endpoint that is to be used needs to be programmed as follows:
– Operating speed in the SPEED bit field (bits 7 and 6).
– Set 01 (binary value) in the PROT field for isochronous transfer.
– Endpoint Number of the target device in RENDPN field. This is the endpoint number contained in
the Rx endpoint descriptor returned by the target device during enumeration.
• The RXMAXP register for the controller endpoint must be written with the maximum packet size (in
bytes) for the transfer. This value should be the same as the wMaxPacketSize field of the Standard
Endpoint Descriptor for the target endpoint.
• The HOST_RXINTERVAL register needs to be written with the required transaction interval (usually
one transaction per frame/microframe).
• The relevant interrupt enable bit in the INTRRXE register should be set (if an interrupt is required for
this endpoint).
• The following bits of HOST_RXCSR register should be set as shown below:
– Set the DMAEN bit ( bit 13) to 1 if a DMA request is required for this endpoint.
– Clear the DISNYET it (bit 12) to 0 to allow normal PING flow control. This will only affect High
Speed transactions.
– Always clear the DMAMODE bit (bit 11) to 0.
• If DMA is enabled, AUTOREQ register can be set for generating IN tokens automatically after receiving
the data. Set the bit field RXn_AUTOREQ (where n is the endpoint number) with binary value 01 or 11.
3.2.4.1.2
Operation
The operation starts with the software setting REQPKT bit of HOST_RXCSR (bit 5). This causes the
controller to send an IN token to the target.
When a packet is received, an interrupt is generated which the software may use to unload the packet
from the FIFO and clear the RXPKTRDY bit in the HOST_RXCSR register (bit 0) in the same way as for a
Bulk Rx endpoint. As the interrupt could occur almost any time within a frame(/microframe), the timing of
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FIFO unload requests will probably be irregular. If the data sink for the endpoint is going to some external
hardware, it may be better to minimize the requirement for additional buffering by waiting until the end of
each frame before unloading the FIFO. This can be done by using the SOF_PULSE signal from the
controller to trigger the unloading of the data packet. The SOF_PULSE is generated once per
frame(/microframe). The interrupts may still be used to clear the RXPKTRDY bit in HOST_RXCSR.
3.2.4.1.3
Error Handling
If a CRC or bit-stuff error occurs during the reception of a packet, the packet will still be stored in the FIFO
but the DATAERR_NAKTIMEOUT bit of HOST_RXCSR (bit 3) is set to indicate that the data may be
corrupt.
3.2.4.2
Isochronous Out Transactions
An Isochronous OUT transaction may be used to transfer periodic data from the host to the USB
peripheral.
Following optional features are available for use with a Tx endpoint used in Host mode to transmit this
data:
• Double packet buffering: When enabled, up to two packets can be stored in the FIFO awaiting
transmission to the peripheral device. Double packet buffering is enabled by setting the DPB bit of
TXFIFOSZ register (bit 4).
• DMA: If DMA is enabled for the endpoint, a DMA request will be generated whenever the endpoint is
able to accept another packet in its FIFO. This feature can be used to allow the DMA controller to load
packets into the FIFO without processor intervention.
However, this feature is not particularly useful with isochronous endpoints because the packets
transferred are often not maximum packet size.
When DMA is enabled and DMAMODE bit in HOST_TXCSR register is set, endpoint interrupt will not
be generated for completion of packet reception. Endpoint interrupt will be generated only in the error
conditions.
3.2.4.2.1
Setup
Before initiating any Isochronous OUT transactions:
• The target function address needs to be set in the TXFUNCADDR register for the selected controller
endpoint (TXFUNCADDR register is available for all endpoints from EP0 to EP4).
• The HOST_TXTYPE register for the endpoint that is to be used needs to be programmed as follows:
– Operating speed in the SPEED bit field (bits 7 and 6).
– Set 01 (binary value) in the PROT field for isochronous transfer.
– Endpoint Number of the target device in TENDPN field. This is the endpoint number contained in
the OUT(Tx) endpoint descriptor returned by the target device during enumeration.
• The TXMAXP register for the controller endpoint must be written with the maximum packet size (in
bytes) for the transfer. This value should be the same as the wMaxPacketSize field of the Standard
Endpoint Descriptor for the target endpoint.
• The HOST_TXINTERVAL register needs to be written with the required transaction interval (usually
one transaction per frame/microframe).
• The relevant interrupt enable bit in the INTRTXE register should be set (if an interrupt is required for
this endpoint).
• The following bits of HOST_TXCSR register should be set as shown below:
– Set the MODE bit (bit 13) to 1 to ensure the FIFO is enabled (only necessary if the FIFO is shared
with an Rx endpoint).
– Set the DMAEN bit ( bit 12) to 1 if a DMA request is required for this endpoint.
– The FRCDATATOG bit (bit 12) is ignored for isochronous transactions.
– Set the DMAMODE bit (bit 10) to 1 when DMA is enabled and the endpoint interrupt is not needed
for each packet transmission.
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Operation
The operation starts when the software writes to the FIFO and sets TXPKTRDY bit of HOST_TXCSR
(bit 0). This triggers the controller to send an OUT token followed by the first data packet from the FIFO.
An interrupt is generated whenever a packet is sent and the software may use this interrupt to load the
next packet into the FIFO and set the TXPKTRDY bit in the HOST_TXCSR register (bit 0) in the same
way as for a Bulk Tx endpoint. As the interrupt could occur almost any time within a frame, depending on
when the host has scheduled the transaction, this may result in irregular timing of FIFO load requests. If
the data source for the endpoint is coming from some external hardware, it may be more convenient to
wait until the end of each frame before loading the FIFO as this will minimize the requirement for
additional buffering. This can be done by using the SOF_PULSE signal from the controller to trigger the
loading of the next data packet. The SOF_PULSE is generated once per frame(/microframe). The
interrupts may still be used to set the TXPKTRDY bit in HOST_TXCSR.
3.3
DMA Operation
The DMA controller sub-module is a common 4 dual-channel DMA controller. It supports 4 TX and 4 RX
channels, and each channel attaches to the associated endpoint in the controller. Channel 0 maps to
Endpoint 1 up to Channel 3 mapping to Endpoint 4, while endpoint 0 cannot utilize the DMA. The DMA is
programmed through parameters stored in the DMA registers, and implements DMAs through the buffer
descriptor chains stored in main memory. The DMA utilizes incrementing addressing mode, and can burst
up to 64 bytes. When a DMA is initiated, the DMA controller reads the current parameters for that channel
from the DMA registers, reads the CPPI buffer descriptor pointed to by the parameters, and performs the
DMA using the data buffer in the descriptor. The DMA controller updates and saves the DMA parameters
when the data is completed. The software can access the current parameters at any time by accessing
the DMA registers.
The DMA controller has a concept of DMA packets which is different from the USB packets. A DMA
packet can be (but not necessarily) of the same size as USB packet. Each DMA packet can comprise of
one or multiple data buffers. Each DMA channel can process one or multiple chains of these DMA
packets.
The controller supports two modes of DMA: transparent mode and RNDIS mode.
3.3.1
DMA Transmit Operation
For transmit operation, the software has to program the DMA channel with a chain of transmit buffers.
3.3.1.1
Transmit Buffer
A Transmit buffer is a contiguous block of memory used to store data for transmission. Each Tx buffer has
a corresponding Tx buffer descriptor. Each Tx buffer can be linked together with other Tx buffers to make
a DMA packet or a queue of DMA packets.
Transmit buffers are byte aligned structures located in processor’s main memory. Tx buffer size may vary
from 1 to 65,535 bytes.
3.3.1.2
Transmit Buffer Descriptor
Tx buffer descriptors provide information about a single corresponding Tx data buffer. Every Tx buffer has
a single Tx buffer descriptor that stores the following information:
• Pointer to the data buffer
• Pointer to the next buffer descriptor in the queue
• Buffer length and offset to the first valid byte of buffer data
• Start of DMA packet (SOP) indicator
• End of DMA packet (EOP) indicator
• Ownership (only valid with SOP)
• End of queue (EOQ) (only valid on EOP)
• Packet Length (only valid with SOP)
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Transmit buffer descriptors contain 16 bytes (4 words) and are 32-bit aligned structures located in
processor’s main memory. Transmit buffer descriptors may be linked together to form packets. Buffer
descriptor SOP and EOP bits are used to delimit packets. Packets in turn may be linked together to form
transmit queue. Each queue consists of a chain of buffer descriptors linked together by Next Descriptor
Pointers. The last buffer descriptor in a queue has a zero Next Descriptor Pointer. Each descriptor points
to a data buffer yielding a queue of buffers.
Four Words of Transmit Buffer Descriptor are described below.
Table 6. Transmit Buffer Descriptor Word 0
Bits
Name
Description
31:0
Next Descriptor
Pointer
The 32-bit word aligned memory address of the next buffer descriptor in the Tx queue. This is the
mechanism used to reference the next buffer descriptor from the current buffer descriptor. If the
value of this pointer is zero then the current buffer is the last buffer in the queue. The software sets
the Next Descriptor Pointer.
Table 7. Transmit Buffer Descriptor Word 1
Bits
Name
Description
31:0
Next Descriptor
Pointer
The Buffer Pointer is the byte aligned memory address of the buffer associated with the buffer
descriptor. The software sets the Buffer Pointer.
Table 8. Transmit Buffer Descriptor Word 2
Bits
Name
Description
31:16
Buffer Offset
The Buffer Offset indicates how many unused bytes are at the start of the buffer (SOP buffers only).
A value of zero indicates that there are no unused bytes at the start of the buffer and that valid data
begins on the first byte of the buffer. A value of 0x000F (decimal 15) indicates that the first 15 bytes
of the buffer are to be ignored by the DMA controller while transmitting and that valid buffer data
starts on byte 16 of the buffer. The Buffer Offset is valid only on Start Of Packet buffer descriptors
and must be zero otherwise. The software sets the Buffer Offset. The Buffer Offset must be less
than the Buffer Length.
15:0
Buffer Length
The Buffer Length field indicates how many valid data bytes are in the buffer. Unused or protocol
specific bytes at the beginning of the buffer are not counted in the Buffer Length field. The software
sets the Buffer Length.
Table 9. Transmit Buffer Descriptor Word 3
Bits
Name
31
SOP
30
29
Value
Start of Packet: SOP Indicates that the descriptor buffer is the first buffer in the packet. The
software sets the SOP bit.
0
Not start of packet buffer
1
Start of packet buffer
EOP
End of Packet: EOP Indicates that the descriptor buffer is the last buffer in the packet. The
software sets the EOP bit.
0
Not end of packet buffer
1
End of packet buffer
Ownership
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Description
The Ownership bit indicates ownership of the DMA packet and is valid only on SOP. This bit
is set by the software and cleared by the DMA controller when the packet has been
transmitted. The software can use this bit to reclaim buffers.
0
The packet is owned by the host processor
1
The packet is owned by the DMA controller
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Table 9. Transmit Buffer Descriptor Word 3 (continued)
Bits
Name
28
EOQ
Value
Description
End of Queue: The End of Queue bit is set by the DMA controller to indicate that all packets
in the queue have been transmitted and the Tx queue is empty. This bit is valid only on when
EOP is set.
0
The Tx queue has more packets to transfer
1
The DMA controller took this descriptor buffer as the last buffer descriptor in the last packet in
the queue
27:24
Reserved
Reserved
23
Zero Byte
Zero Byte Packet Identifier. This bit is set by the software when a zero byte USB packet
needs to be transmitted. This bit tells the DMA controller that no data transfer needs to be
done for transmitting this zero byte data buffer.
22:16
Reserved
Reserved
15:0
Packet Length
The length of the DMA packet in bytes. This field is valid only on SOP and is written by the
software. If the Packet Length is less than the sum of the buffer lengths, then the packet data
will be truncated. A Packet Length greater than the sum of the buffers is a software error.
Four different cases are possible for the number of buffers in a DMA packet:
1. Buffer Descriptor contains Start of Packet field and End of Packet field (1 buffer in DMA packet).
2. Buffer Descriptor contains Start of Packet field only (2+ buffers in DMA packet).
3. Buffer Descriptor contains End of Packet field only (2+ buffers in DMA packet).
4. Buffer Descriptor does not contain either of Start of Packet field and End of Packet field (3+ buffers in
packet).
3.3.1.3
Transmit DMA State
The DMA controller stores and maintains state information for each transmit channel. The state
information is referred to as the Tx DMA State. The Tx DMA State is a combination of control fields and
DMA controller specific scratchpad space used to manipulate data structures and transmit DMA packets.
The Tx DMA State is stored in registers TCPPIDMASTATEW0, TCPPIDMASTATEW1,
TCPPIDMASTATEW2, TCPPIDMASTATEW3, TCPPIDMASTATEW4, TCPPIDMASTATEW5 and
TCPPICOMPPTR for each channel.
Each channel has one queue. The queue has one head descriptor pointer and one completion pointer.
The following information is stored in the Tx DMA State:
• TCPPIDMASTATEW0: Tx Queue Head Descriptor Pointer(s)
• TCPPICOMPPTR: Tx Completion Pointer(s)
• TCPPIDMASTATEW1: Start of Packet Buffer Descriptor Pointer
• TCPPIDMASTATEW2: Current Buffer Descriptor Pointer
• TCPPIDMASTATEW3: Current Buffer Pointer
• TCPPIDMASTATEW5: Remaining DMA Packet Length and Actual DMA Packet Length
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3.3.1.4
Transmit Queues
The transmit queue provides a logical queue of DMA packets for transmission through a channel. Each
channel has one dedicated queue. Each queue has one associated Tx Queue Head Descriptor Pointer
and one associated Tx Completion Pointer contained in the channel Tx DMA State. The Tx queue is a
linked list of Tx buffer descriptors that constitute one or more packets queued for transmission. Packets
are added to the tail of the list by the software and packets are freed from the head of the list by the DMA
controller as each packet transmission is completed.
Figure 14 shows a Tx queue.
Figure 14. Tx Queue Flow Chart
SOP descriptor
Buffer
Descriptor
Buffer
EOP descriptor
Buffer
Tx queue head descriptor pointer
3.3.1.5
•
•
•
•
•
•
Operation
After reset the software must write zeroes to all Tx DMA State registers (TCPPIDMASTATEW0,
TCPPIDMASTATEW1, TCPPIDMASTATEW2, TCPPIDMASTATEW3, TCPPIDMASTATEW4,
TCPPIDMASTATEW5).
The software constructs transmit queues in memory (one or more DMA packets for transmission)
Enable DMA for the endpoint in the PERI_TXCSR or HOST_TXCSR by setting the DMAEN bit.
Enable the DMA ports by setting TCPPI_ENABLE bit of TCPPICR register.
Write the head of the queue descriptor pointer to the TCPPIDMASTATEW0 register to start the DMA.
The USB controller will start transmitting data. Interrupt associated with the DMA channel is asserted,
after each DMA packet is transmitted.
For each buffer added to a transmit queue, the software must initialize the Tx buffer descriptor values as
follows:
• Write the Next Descriptor Pointer with the 32-bit aligned address of the next descriptor in the queue
(zero if last descriptor)
• Write the Buffer Pointer with the byte aligned address of the buffer data
• Write the Buffer Length with the number of bytes in the buffer
• Write the Buffer Offset with the number of bytes in the offset to the data (nonzero with SOP only)
• Set the SOP, EOP, and Ownership bits as appropriate
• Clear the End Of Queue bit
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The DMA controller begins Tx DMA packet transmission on a given channel when the host writes the
channel’s Tx queue head descriptor pointer with the address of the first buffer descriptor in the queue
(nonzero value). Each channel may have one or more queues, so each channel may have one or more
head descriptor pointers. The first buffer descriptor for each Tx DMA packet must have the Start of Packet
(SOP) bit and the Ownership bit set to one by the software. The last buffer descriptor for each Tx DMA
packet must have the End of Packet (EOP) bit set to one by the software. The DMA controller will transmit
DMA packets until all queued packets have been transmitted and the queue is empty. When each packet
transmission is complete, the DMA controller will clear the Ownership bit in the DMA packet’s SOP buffer
descriptor and issue an interrupt to the processor by writing the DMA packet’s last buffer descriptor
address to the queue’s Tx DMA State Completion Pointer (TCPPICOMPPTR register). When the last
packet in a queue has been transmitted, the DMA controller sets the End Of Queue bit in the EOP buffer
descriptor, clears the Ownership bit in the SOP Descriptor, zeroes the appropriate DMA state head
descriptor pointer, and then issues a Tx interrupt to the host by writing address of the last buffer descriptor
processed by the DMA controller to the queue’s associated Tx completion pointer (TCPPICOMPPTR
register).
On interrupt from the port, the software can process the buffer queue, detecting transmitted packets by the
status of the Ownership bit in the SOP buffer descriptor. If the Ownership bit is cleared to zero, then the
packet has been transmitted and the software may reclaim the buffers associated with the packet. The
software continues queue processing until the end of the queue or until a SOP buffer descriptor is read
that contains a set Ownership bit indicating that the packet transmission is not complete. The software
determines that all packets in the queue have been transmitted when the last packet in the queue has a
cleared Ownership bit in the SOP buffer descriptor, the End of Queue bit is set in the last packet EOP
buffer descriptor, and the Next Descriptor Pointer of the last packet EOP buffer descriptor is zero.
The software acknowledges an interrupt by writing the address of the last buffer descriptor to the queue’s
associated Tx Completion Pointer (TCPPICOMPPTR register).
If the software written buffer address value in TCCPICOMPPTR register is different from the buffer
address written by the DMA controller after Tx completion, then the interrupt for the Tx Channel remains
asserted. If the software-written buffer address value matches with the buffer address written by the DMA
controller, the Tx Channel interrupt gets deasserted.
A misqueued packet condition may occur when the software adds a packet to a queue for transmission as
the DMA controller finishes transmitting the previous last packet in the queue. The misqueued packet is
detected by the software when queue processing detects a cleared Ownership bit in the SOP buffer
descriptor, a set End of Queue bit in the EOP buffer descriptor, and a nonzero Next Descriptor Pointer in
the EOP buffer descriptor. A misqueued packet means that the DMA controller read the last EOP buffer
descriptor before the host added the new last packet to the queue, so the DMA controller determined
queue empty just before the last packet was added. The host software corrects the misqueued packet
condition by initiating a new packet transfer for the misqueued packet by writing the misqueued packet’s
SOP buffer descriptor address to the head descriptor pointer in TCCPIDMASTATEW0 register.
3.3.1.6
Transparent Mode and RNDIS Mode Transmit DMA Operation
Transparent Mode DMA operation is the default DMA mode (as described in previous section) where an
interrupt is generated whenever a DMA packet is transmitted. In the transparent mode, DMA packet size
cannot be greater than USB MaxPktSize for the endpoint. This means, for transmitting say ‘n’ USB
packets, the DMA controller should be programmed with a queue of ‘n’ DMA packets.
RNDIS mode DMA is used to transmit DMA packets which are larger than USB MaxPktSize. This is
accomplished by breaking the larger packet into smaller packets, not larger than USB MaxPktSize. This
implies that the data to be transmitted will be sent over USB in multiple packets of MaxPktSize and the Tx
DMA interrupt for the channel is generated after the transmission of complete DMA packet. This mode of
DMA is used for RNDIS type transfers over USB. The protocol defines the end of the complete transfer by
sending a short USB packet (smaller than USB MaxPktSize as mentioned in USB specification 2.0). If the
DMA packet size is an exact multiple of USB MaxPktSize, the DMA controller sends a zero byte packet at
the end of complete transfer to signify the completion of the transfer.
RNDIS Mode DMA is supported only when USB MaxPktSize is an integral multiple of 64 bytes.
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RNDIS Mode Setup
The setup of RNDIS mode DMA is similar to the default Transparent Mode as mentioned in the previous
section. The following steps need to be taken for setting up RNDIS mode Tx DMA:
• After reset the software must write zeroes to all Tx DMA State registers (TCPPIDMASTATEW0,
TCPPIDMASTATEW1,
TCPPIDMASTATEW2,
TCPPIDMASTATEW3,
TCPPIDMASTATEW4,
TCPPIDMASTATEW5).
• The software constructs a transmit queue in memory (one or more DMA packets for transmission).
• Enable DMA for the endpoint in the PERI_TXCSR or HOST_TXCSR by setting the DMAEN bit.
• Enable the DMA ports by setting TCPPI_ENABLE bit of TCPPICR register.
• Set RNDIS bit of CTRLR register for enabling RNDIS mode for all channels or set TXnEN bit of
RNDISR register for specific DMA channel n.
• Write the head of the queue descriptor pointer to the TCPPIDMASTATEW0 register to start the DMA.
• The USB controller will start transmitting data.
• If the DMA packet size is exact multiple of USB MaxPktSize, a zero byte packet is transmitted and
interrupt associated with the DMA channel is asserted.
• If the DMA packet size is not exact multiple of USB MaxPktSize, the last USB packet transmitted is a
short packet and interrupt associated with the DMA channel is asserted.
Transparent Mode Setup
Transparent DMA configuration is identical to RNDIS DMA configuration with the exception that each
packet is defined by a single buffer descriptor with SOP and EOP bit fields set. Packet size is not bounded
to be a multiple of 64 bytes but by max packet size. CTRLR.RNDIS bit field should be cleared to zero.
3.3.1.7
DMA Channel TearDown
The DMA also supports a teardown operation on TX channels. Teardown allows software to terminate the
current Tx queue by notifying the DMA. The DMA will stop the current Tx DMA for that channel, and
update the channel parameters to remove all Tx descriptors from that queue. Then the software is free to
reclaim the buffers without worry of interrupting the DMA in progress.
Teardown of Tx channels is done using the TCPPITDR register. If the READY bit of TCPPITDR register is
set, it signifies that the Tx channel can be torn down. The channel number should be written in the
CHANNEL field of TCPPITDR register to teardown the channel.
Note that the software must also teardown the core after the DMA. Software should specify that the
following steps are all completed before assuming teardown has completed successfully.
1. After tearing down the channel, DMA interrupt should be generated and the TCPPICOMPPTR register
will be 0xFFFFFFFC. This indicates that the DMA has completed the teardown and all the data buffers
can be reclaimed.
2. The software must set the FLUSHFIFO bit of the PERI_TXCSR or HOST_TXCSR register for the
endpoint to be torn down.
After both the DMA and the core are torn down, the DMA channel and endpoint can be restarted cleanly.
A failure to perform either of these steps could result in data loss or spurious data upon restart.
3.3.2
DMA Receive Operation
For receive operation, the software has to program the DMA channel with a chain of receive buffers.
3.3.2.1
Receive Buffer
A receive buffer is a contiguous block of memory used to store received data. Each Rx buffer has a
corresponding Rx buffer descriptor. Each Rx buffer can be linked together with other Rx buffers to make a
DMA packet or a queue of DMA packets.
Receive buffers are byte aligned structures located in processor’s main memory. Rx buffer size may vary
from 1 to 65,535 bytes.
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Receive Buffer Descriptor
Rx buffer descriptors provide information about a single corresponding Rx data buffer. Every Rx buffer has
a single Rx buffer descriptor that stores the following information:
• Pointer to the data buffer
• Pointer to the next buffer descriptor in the queue
• Buffer length and offset to the first valid byte of buffer data
• Start of DMA packet (SOP) indicator
• End of DMA packet (EOP) indicator
• Ownership (only valid with SOP)
• End of queue (EOQ) (only valid on EOP)
• Packet Length (only valid with SOP)
Receive buffer descriptors contain 16 bytes (4 words) and are 32-bit aligned structures located in
processor’s main memory. Receive buffer descriptors may be linked together to form packets. Buffer
descriptor SOP and EOP bits are used to delimit packets. Packets in turn may be linked together to form a
receive queue. Each queue consists of a chain of buffer descriptors linked together by Next Descriptor
Pointers. The last buffer descriptor in a queue has a zero Next Descriptor Pointer. Each descriptor points
to a data buffer yielding a queue of buffers.
Four Words of Receive Buffer Descriptor are described in Table 10 through Table 13.
Table 10. Receive Buffer Descriptor Word 0
Bits
Name
Description
31:0
Next Descriptor
Pointer
The 32-bit word aligned memory address of the next buffer descriptor in the Rx queue. This is the
mechanism used to reference the next buffer descriptor from the current buffer descriptor. If the
value of this pointer is zero then the current buffer is the last buffer in the queue. The software sets
the Next Descriptor Pointer.
Table 11. Receive Buffer Descriptor Word 1
Bits
Name
Description
31:0
Buffer Pointer
The Buffer Pointer is the byte aligned memory address of the buffer associated with the buffer
descriptor. The software sets the Buffer Pointer.
Table 12. Receive Buffer Descriptor Word 2
64
Bits
Name
Description
31:16
Buffer Offset
The Buffer Offset indicates how many unused bytes are at the start of the buffer (SOP buffers only).
A value of zero indicates that there are no unused bytes at the start of the buffer and that valid data
begins on the first byte of the buffer. A value of 0x000F (decimal 15) indicates that the first 15 bytes
of the buffer are to be ignored by the DMA controller while transmitting and that valid buffer data
starts on byte 16 of the buffer. The software sets the buffer offset to zero on buffer initialization and
the DMA controller overwrites the zero value on SOP packets with the Rx DMA State buffer offset
value.
15:0
Buffer Length
The Buffer Length field indicates how many valid data bytes are in the buffer. Unused or protocol
specific bytes at the beginning of the buffer are not counted in the Buffer Length field. The software
sets the buffer length on buffer initialization. The DMA controller will overwrite the software initialized
value on an EOP buffer when the number of received data bytes is less than the host initiated value.
The DMA controller will overwrite the host initialized value on SOP when the Buffer Offset is greater
than zero, or the Packet Length is less than the buffer length.
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Table 13. Receive Buffer Descriptor Word 3
Bit
Field
31
SOP
30
29
28
Value
Description
Start of Packet: SOP Indicates that the descriptor buffer is the first buffer in the packet. The
software sets the SOP bit.
0
Not start of packet buffer
1
Start of packet buffer
EOP
End of Packet: EOP Indicates that the descriptor buffer is the last buffer in the packet. The
software sets the EOP bit.
0
Not end of packet buffer
1
End of packet buffer
Ownership
The Ownership bit indicates ownership of the DMA packet and is valid only on SOP. This bit
is set by the software and cleared by the DMA controller when the packet has been
transmitted. The software can use this bit to reclaim buffers.
0
The packet is owned by the host processor
1
The packet is owned by the DMA controller
EOQ
End of Queue: The End of Queue bit is set by the DMA controller to indicate that all packets
in the queue have been transmitted and the Tx queue is empty. This bit is valid only on when
EOP is set.
0
The Tx queue has more packets to transfer
1
The DMA controller took this descriptor buffer as the last buffer descriptor in the last packet in
the queue
27:24
Reserved
Reserved
23
Zero Byte
Zero Byte Packet Identifier. This bit is set by the software when a zero byte USB packet
needs to be transmitted. This bit tells the DMA controller that no data transfer needs to be
done for transmitting this zero byte data buffer.
22:16
Reserved
15:0
Packet Length
The length of the DMA packet in bytes. This field is valid only on SOP and is written by the
software. If the Packet Length is less than the sum of the buffer lengths, then the packet data
will be truncated. A Packet Length greater than the sum of the buffers is a software error.
Four different cases are possible for the number of buffers in a DMA packet:
1. Buffer Descriptor contains Start of Packet field and End of Packet field (1 buffer in DMA packet)
2. Buffer Descriptor contains Start of Packet field only (2+ buffers in DMA packet)
3. Buffer Descriptor contains End of Packet field only (2+ buffers in DMA packet)
4. Buffer Descriptor does not contain either of Start of Packet field and End of Packet field (3+ buffers in
packet)
3.3.2.3
Receive DMA State
The DMA controller stores and maintains state information for each receive channel. The state information
is referred to as the Rx DMA State. The Rx DMA State is a combination of control fields and DMA
controller specific scratchpad space used to manipulate data structures and receive DMA packets. The Rx
DMA State is stored in registers RCPPIDMASTATEW0, RCPPIDMASTATEW1, RCPPIDMASTATEW2,
RCPPIDMASTATEW3, RCPPIDMASTATEW4, RCPPIDMASTATEW5, RCPPIDMASTATEW6 and
RCPPICOMPPTR for each channel.
Each channel has one receive queue that has a head descriptor pointer and one completion pointer.
The following information is stored in the Tx DMA State:
• RCPPIDMASTATEW0: Rx Queue Head Descriptor Pointer
• RCPPICOMPPTR: Rx Completion Pointer
• RCPPIDMASTATEW2: Start of Packet Buffer Descriptor Pointer
• RCPPIDMASTATEW3: Current Buffer Descriptor Pointer
• RCPPIDMASTATEW4: Current Buffer Pointer
• RCPPIDMASTATEW5: Remaining DMA Packet Length and Actual DMA Packet Length
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Receive Queue
The receive queue provides a logical queue of processor memory space for DMA packets to be received
from DMA controller channel. Each channel has single Rx queue. Each queue has one associated Rx
Queue Head Descriptor Pointer and one associated Rx Completion Pointer contained in the channel Rx
DMA State. The Rx queue is linked lists of Rx buffer descriptors that constitute processor memory space
for one or more packets to be received. Packet space is added to the tail of the list by the software and
received packets are freed from the list by the DMA controller as each packet is received.
Figure 15 shows an Rx Queue.
Figure 15. Rx Queue Flow Chart
SOP Descriptor
Buffer
Descriptor
Buffer
Descriptor
Buffer
Descriptor
Buffer
EOP Descriptor
Buffer
Rx queue head descriptor pointer
3.3.2.5
•
•
•
•
•
•
•
66
Operation
After reset the software must write zeroes to all Rx DMA State registers (RCPPIDMASTATEW0,
RCPPIDMASTATEW1, RCPPIDMASTATEW2, RCPPIDMASTATEW3, RCPPIDMASTATEW4,
RCPPIDMASTATEW5 and RCPPIDMASTATEW6).
The software constructs the receive queue in memory.
Enable DMA for the endpoint in the PERI_RXCSR or HOST_RXCSR by setting the DMAEN bit.
Enable the DMA ports by setting RCPPI_ENABLE bit of RCPPICR register.
Set the value in RXBUFCNTn register (where n is the channel number) for the number of buffers
available in the Rx queue. The minimum value should be 3 for the Rx DMA to start operation. The
value in RXBUFCNTn decrements as DMA controller consumes the buffers for reception.
Write the head of the queue descriptor pointer to the RCPPIDMASTATEW1 register to start the DMA.
The USB controller will send IN token and wait for the data on the bus. Once data is received, DMA
controller will transfer the data in the Rx queue from the endpoint FIFO. Once a complete DMA packet
is received, interrupt associated with the DMA channel is asserted.
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The software enables packet reception on a given channel by writing the address of the first buffer
descriptor in the queue (nonzero value) to the channel’s head descriptor pointer (RCCPIDMASTATEW1)
in the channel’s Rx DMA state. When packet reception begins on a given channel, the DMA controller fills
each Rx buffer with data in order starting with the first buffer and proceeding through the Rx queue. If the
Buffer Offset in the Rx DMA State is nonzero, then the controller will begin writing data after the offset
number of bytes in the SOP buffer. The DMA controller performs the following operations at the end of
each packet reception:
• Overwrite the buffer length in the packet’s EOP buffer descriptor with the number of bytes actually
received in the packet’s last buffer. The software initialized value is the buffer size. The overwritten
value will be less than or equal to the software initialized value.
• Set the EOP bit in the packet’s EOP buffer descriptor.
• Set the EOQ bit in the packet’s EOP buffer descriptor if the current packet is the last packet in the
queue.
• Overwrite the packet’s SOP buffer descriptor Buffer Offset with the Rx DMA state value (the software
initialized the buffer descriptor Buffer Offset value to zero). All non SOP buffer descriptors must have a
zero Buffer Offset initialized by the host.
• Overwrite the packet’s SOP buffer descriptor buffer length with the number of valid data bytes in the
buffer. If the buffer is filled up, the buffer length will be the buffer size minus buffer offset.
• Set the SOP bit in the packet’s SOP buffer descriptor.
• Write the SOP buffer descriptor Packet Length field.
• Clear the Ownership bit in the packet’s SOP buffer descriptor.
• Issue an Rx DMA interrupt to the host processor by writing the address of the packet’s last buffer
descriptor to the queue’s Rx DMA State Completion Pointer (RCPPICOMPPTR register).
On interrupt the software processes the Rx buffer queue detecting received packets by the status of
the Ownership bit in each packet’s SOP buffer descriptor. If the Ownership bit is cleared then the
packet has been completely received and is available to be processed by the software. The software
may continue Rx queue processing until the end of the queue or until a buffer descriptor is read that
contains a set Ownership bit indicating that the next packet’s reception is not complete. The software
determines that the Rx queue is empty when the last packet in the queue has a cleared Ownership bit
in the SOP buffer descriptor, a set End of Queue bit in the EOP buffer descriptor, and the Next
Descriptor Pointer in the EOP buffer descriptor is zero.
The software acknowledges an interrupt by writing the address of the last buffer descriptor to the
queue’s associated Rx Completion Pointer (RCPPICOMPPTR register).
If the software written buffer address value in RCCPICOMPPTR register is different from the buffer
address written by the DMA controller after Rx completion, then the interrupt for the Rx Channel
remains asserted. If the software written buffer address value matches with the buffer address written
by the DMA controller, the Rx Channel interrupt gets deasserted.
A misqueued buffer may occur when the software adds buffers to a queue as the DMA controller
finishes the reception of the previous last packet in the queue. The misqueued buffer is detected by the
software when queue processing detects a cleared Ownership bit in the SOP buffer descriptor, a set
End of Queue bit in the EOP buffer descriptor, and a nonzero Next Descriptor Pointer in the EOP
buffer descriptor. A misqueued buffer means that the DMA controller read the last EOP buffer
descriptor before the software added buffer descriptor(s) to the queue, so the DMA controller
determined queue empty just before the software added more buffer descriptor(s). Receive overrun
condition may occur in the misqueued buffer case. If a new packet reception is begun during the time
that the DMA controller has determined the end of queue condition, then the received packet will
overrun (start of packet overrun). If the misqueued buffer occurs during the middle of a packet
reception then middle of packet overrun may occur. If the misqueued buffer occurs after the last packet
has completed, and is corrected before the next packet reception begins, then overrun will not occur.
The software acts on the misqueued buffer condition by writing the added buffer descriptor address to
the appropriate Rx DMA State Head Descriptor Pointer in RCPPIDMASTATEW1 register.
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Receive Abort Handling
The DMA controller sets ‘Rx Abort’ bit used to identify Rx packets which were aborted due to lack of
buffers. Software must take care to inspect any Rx SOP packet for this bit and ignore all the buffers in that
packet as the packet is incomplete. Also, for aborted packets, the packet length may not match the data
size in the buffers.
3.3.2.7
Transparent Mode and RNDIS Mode Receive DMA Operation
Transparent Mode DMA operation is the default DMA mode (as described in previous section) where an
interrupt is generated whenever a DMA packet is received. In the transparent mode, DMA packet size
cannot be greater than USB MaxPktSize for the endpoint. This means, for receiving say n USB packets,
the DMA controller should be programmed with a queue of minimum n DMA packets. RXBUFCNT register
also needs to be written with value n. The number n should be greater than 3 as the RXBUFCNT register
should have at least 3 packets for the Rx DMA to receive packets from the endpoint FIFO.
RNDIS mode DMA is used to receive DMA packets which are larger than USB MaxPktSize. This is
accomplished by breaking the larger packet into smaller packets, not larger than USB MaxPktSize. This
implies that multiple USB packets of MaxPktSize will be received and transferred together as a single
large DMA packet and the DMA interrupt is generated only at the end of the complete reception of DMA
packet. This mode of DMA is used for RNDIS type transfers over USB. The protocol defines the end of the
complete transfer by receiving a short USB packet (smaller than USB MaxPktSize as mentioned in USB
specification 2.0). If the DMA packet size is an exact multiple of USB MaxPktSize, the DMA controller
waits for a zero byte packet at the end of complete transfer to signify the completion of the transfer.
RNDIS Mode DMA is supported only when USB MaxPktSize is an integral multiple of 64 bytes.
RNDIS Mode Setup
The setup of RNDIS mode DMA is similar to the default Transparent Mode as mentioned in the previous
section. The following steps need to be taken for setting up RNDIS mode Rx DMA:
• After reset the software must write zeroes to all Rx DMA State registers (RCPPIDMASTATEW0,
RCPPIDMASTATEW1,
RCPPIDMASTATEW2,
RCPPIDMASTATEW3,
RCPPIDMASTATEW4,
RCPPIDMASTATEW5 and RCPPIDMASTATEW6).
• The software constructs the receive queue in memory.
• Enable DMA for the endpoint in the PERI_RXCSR or HOST_RXCSR by setting the DMAEN bit.
• Enable the DMA ports by setting RCPPI_ENABLE bit of RCPPICR register.
• Set RNDIS bit of CTRLR register for enabling RNDIS mode for all channels or set TXnEN bit of
RNDISR register for specific DMA channel n.
• Set the value in RXBUFCNTn register (where n is the channel number) for the number of buffers
available in the Rx queue. The minimum value should be 3 for the Rx DMA to start operation. The
value in RXBUFCNTn decrements as DMA controller consumes the buffers for reception.
• Write the head of the queue descriptor pointer to the RCPPIDMASTATEW1 register to start the DMA.
• The USB controller will send IN token and wait for the data on the bus. Once data is received, DMA
controller will transfer the data in the Rx queue from the endpoint FIFO. Once a complete DMA packet
is received, the interrupt associated with the DMA channel is asserted.
• If the DMA packet size is exact multiple of USB MaxPktSize, a zero byte packet is expected and
interrupt associated with the DMA channel is asserted when that zero byte packet is received.
• If the DMA packet size is not exact multiple of USB MaxPktSize, the last USB packet received is a
short packet and interrupt associated with the DMA channel is asserted.
An additional feature of automatically generating IN tokens is available. This feature is used in USB Host
mode operation of the USB controller. This feature is functional in RNDIS mode DMA only. To
automatically generate the IN tokens while receiving data, set the field RXn_AUTOREQ (where n is the
channel number) of AUTOREQ register with binary 01. In this case, IN tokens will be generated and sent
to the target USB peripheral device after every successfully received packet. No IN token will be
generated after the End Of DMA Packet is reached. Rx DMA interrupt is generated after the complete
reception.
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If RXn_AUTOREQ (where n is the channel number) of AUTOREQ register is set with binary 11, IN tokens
will be generated and sent to the target USB peripheral device even after the End Of DMA Packet is
reached. This feature is useful to keep data reception operational across multiple DMA packets in a Rx
queue. The host processor does not have to restart sending IN tokens for every DMA packet in the Rx
queue.
Transparent Mode Setup
Transparent receive DMA configuration is identical to RNDIS DMA configuration with the exception of the
following:
• Each packet is defined by a single buffer descriptor with SOP and EOP bit fields set.
• Packet size is not bounded to be a multiple of 64 byte but by max packet size.
• CTRLR.RNDIS bit field should be cleared to zero.
• RXn:AUTOREQ register field is programmed with the value of 0, which is programmed for no Auto
Request.
3.4
Interrupt Handling
Table 14 lists the interrupts generated by the USB controller.
Table 14. Interrupts Generated by the USB Controller
Interrupt
Description
Tx Endpoint [4:0]
Tx endpoint ready or error condition. For endpoints 4 to 0. (Rx and Tx for endpoint 0)
Rx Endpoint [4:1]
Rx endpoint ready or error condition. For endpoints 4 to 1. (Endpoint 0 has interrupt status in
Tx interrupt)
USB Core[8:0]
Interrupts for 9 USB conditions
DMA Tx Completion [3:0]
Tx DMA completion interrupt for channel 3 to 0
DMA Rx Completion [3:0]
Rx DMA completion interrupt for channel 3 to 0
Whenever any of these interrupt conditions are generated, the host processor is interrupted. The software
needs to read the different interrupt status registers (discussed in later section) to determine the source of
the interrupt.
The nine USB interrupt conditions are listed in Table 15.
Table 15. USB Interrupt Conditions
Interrupt
Description
USB[8]
DRVVBUS level change
USB[7]
VBus voltage < VBus Valid Threshold (VBus error)
USB[6]
SRP detected
USB[5]
Device Disconnected (Valid in Host Mode)
USB[4]
Device Connected (Valid in Host Mode)
USB[3]
SOF started
USB[2]
Reset Signaling detected (In Peripheral Mode)
Babble detected (In Host Mode)
USB[1]
Resume signaling detected
USB[0]
Suspend Signaling detected
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USB Core Interrupts
Interrupt status can be determined using the INTSRCR (interrupt source) register. This register is
non-masked. To clear the interrupt source, set the corresponding interrupt bit in INTCLRR register. For
debugging purposes, interrupt can be set manually through INTSETR register.
The interrupt controller provides the option of masking the interrupts. A mask can be set using
INTMSKSETR register and can be cleared by setting the corresponding bit in the INTMSKCLRR register.
The mask can be read from INTMSKR register. The masked interrupt status is determined using the
INTMASKEDR register.
The host processor software should write to the End Of Interrupt Register (EOIR) to acknowledge the
completion of an interrupt.
Note:
3.4.2
While EOIR is not written, the interrupt from the USB controller remains asserted.
DMA Interrupts
Interrupt status for the DMA interrupts is determined by TCCPIRAWSR and RCPPIRAWSR registers.
These are the raw interrupt status registers for DMA interrupts.
Tx DMA interrupts mask is set using TCPPIENSETR register and cleared using TCPPIIENCLRR register.
The masked status is read using TCPPIMSKSR register.
Rx DMA interrupts mask is set using RCPPIENSETR register and cleared using RCPPIIENCLRR register.
The masked status is read using RCPPIMSKSR register.
Like USB core interrupts, TCCPIEOIR and RCCPIEOIR registers need to be written by the host processor
software to acknowledge the completion of the interrupt.
3.5
Test Modes
The controller supports the four USB 2.0 test modes defined for High-speed functions. It also supports an
additional “FIFO access” test mode that can be used to test the operation of the CPU interface, the DMA
controller (if configured) and the RAM block.
The test modes are entered by writing to the TestMode register (offset address 0x40F). At test mode is
usually requested by the host sending a SET_FEATURE request to Endpoint 0. When the software
receives the request, it should wait until the Endpoint 0 transfer has completed (when it receives the
Endpoint 0 interrupt indicating the status phase has completed) then write to the TestMode register.
Note:
3.5.1
These test modes have no purpose in normal operation.
TEST_SE0_NAK
To enter the Test_SE0_NAK test mode, the software should set the Test_SE0-NAK bit by writing 0x01 to
the TestMode register. The controller will then go into a mode in which it responds to any valid IN token
with a NAK.
3.5.2
TEST_J
To enter the Test_J test mode, the software should set the Test_J bit by writing 0x02 to the TestMode
register. The controller will then go into a mode in which it transmits a continuous J on the bus.
3.5.3
Test_K
To enter the Test_K test mode, the software should set the Test_K bit by writing 0x04 to the TestMode
register. The controller will go into a mode in which it transmits a continuous K on the bus.
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3.5.4
Test_Packet
To execute the Test_Packet, the software should:
1. Start a session (if the core is being used in Host mode).
2. Write the standard test packet (shown below) to the Endpoint 0 FIFO.
3. Write 0x8 to the TestMode register to enter Test_Packet test mode.
4. Set the TxPktRdy bit in the CSR0 register (D1).
The 53 by test packet to load is as follows (all bytes in hex). The test packet only has to be loaded once;
the controller will keep re-sending the test packet without any further intervention from the software.
00
00
00
00
AA
AA
AA EE
EE
EE FE
FF
00
AA
00
00 00
00
EE
AA AA AA AA
FF
EE EE EE EE
FF
FF
FF FF
FF
FF
FF
FF
FF
7F BF
EF
F7
FB
FD FC 7E BF DF
EF
F7
FB
FD
DF
7E
This data sequence is defined in Universal Serial Bus Specification Revision 2.0, Section 7.1.20. The
controller will add the DATAA0 PID to the head of the data sequence and the CRC to the end.
3.5.5
FIFO_ACCESS
The FIFO Access test mode allows the user to test the operation of CPU Interface, the DMA controller (if
configured) and the RAM block by loading a packet of up to 64 bytes into the Endpoint 0 FIFO and then
reading it back out again. Endpoint 0 is used because it is a bi-directional endpoint that uses the same
area of RAM for its Tx and Rx FIFOs.
Note:
The core does not need to be connected to the USB bus to run this test. If it is connected,
then no session should be in progress when the test is run.
The test procedure is as follows:
1. Load a packet of up to 64 bytes into the Endpoint 0 Tx FIFO.
2. Set CSR0.TxPktRdy.
3. Write 0x40 to the Testmode register.
4. Unload the packet from the Endpoint Rx FIFO, again.
5. Set CSR0.ServicedRxPktRdy
Writing 0x40 to the Testmode register causes the following sequence of events:
1. The Endpoint 0 CPU pointer (which records the number of bytes to be transmitted) is copied to the
Endpoint 0 USB pointer (which records the number of bytes received).
2. The Endpoint 0 CPU pointer is reset.
3. CSR0.TxPktRdy is cleared.
4. CSR0.RxPktRdy is set.
5. An Endpoint 0 interrupt is generated (if enabled).,
The effect of these steps is to make the Endpoint 0 controller act as if the packet loaded into the Tx FIFO
has flushed and the same packet received over the USB. The data that was loaded in the Tx FIFO can
now be read out of the Rx FIFO.
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FORCE_HOST
The Force Host test mode enables the user to instruct the core to operate in Host mode, regardless of
whether it is actually connected to any peripheral, i.e., the state of the CID input and the LINESTATE and
HOSTDISCON signals are ignored. (While in this mode, the state of the HOSTDISCON signal can be read
from bit 7 of the DevCtl register.)
This mode, which is selected by setting bit 7 within the Testmode register, allows implementation of the
USB Test_Force_Enable (7.1.20). It can also be used for debugging PHY problems in hardware.
While the Force_Host bit remains set, the core will enter Host mode when the Session bit is set and
remain in Host mode until the Session bit is cleared even if a connected device is disconnected during the
session. The operating speed while in this mode is determined for the sitting of the Force_HS and
Force_FS bits of the Testmode register.
3.6
Reset Considerations
The USB controller has two reset sources: hardware reset and the soft reset (RESET bit in CTRLR
register).
3.6.1
Software Reset Considerations
When the RESET bit in CTRLR is set, all the USB controller registers and DMA operations are reset. The
bit is cleared automatically.
A software reset on the ARM CPU does not affect the register values and operation of the USB controller.
3.6.2
Hardware Reset Considerations
When a hardware reset is asserted, all the registers are set to their default values.
3.7
Interrupt Support
The USB peripheral presents a single interrupt to the ARM interrupt controller (AINTC). For information on
the mapping of interrupts, refer to the device-specific data manual.
3.8
DMA Event Support
The USB is an internal bus master peripheral and therefore does not utilize any EDMA events.
3.9
Power Management
The USB controller can be placed in reduced power modes to conserve power during periods of low
activity. The power management of the peripheral is controlled by the processor Power and Sleep
Controller (PSC). The PSC acts as a master controller for power management for all of the peripherals on
the device. For detailed information on power management procedures using the PSC, see the
TMS320DM335 Digital Media System-on-Chip (DMSoC) ARM Subsystem Reference Guide (SPRUFX7).
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4
Registers
Table 16 lists the memory-mapped registers for the universal serial bus (USB). See the device-specific
data manual for the memory address of these registers. The base address is 01C64x.
Note:
In some cases, a single register address can have different names or meanings depending
on the mode (host/peripheral) or the setting of the index register. The meaning of some bit
fields varies with the mode.
Table 16. Universal Serial Bus (USB) Registers
Offset
Acronym
Register Description
4h
CTRLR
Control Register
Section 4.1
Section
8h
STATR
Status Register
Section 4.2
10h
RNDISR
RNDIS Register
Section 4.3
14h
AUTOREQ
Autorequest Register
Section 4.4
20h
INTSRCR
USB Interrupt Source Register
Section 4.5
24h
INTSETR
USB Interrupt Source Set Register
Section 4.6
28h
INTCLRR
USB Interrupt Source Clear Register
Section 4.7
2Ch
INTMSKR
USB Interrupt Mask Register
Section 4.8
30h
INTMSKSETR
USB Interrupt Mask Set Register
Section 4.9
34h
INTMSKCLRR
USB Interrupt Mask Clear Register
Section 4.10
38h
INTMASKEDR
USB Interrupt Source Masked Register
Section 4.11
3Ch
EOIR
USB End of Interrupt Register
Section 4.12
40h
INTVECTR
USB Interrupt Vector Register
Section 4.13
80h
TCPPICR
Transmit CPPI Control Register
Section 4.14
84h
TCPPITDR
Transmit CPPI Teardown Register
Section 4.15
88h
TCPPIEOIR
Transmit CPPI DMA Controller End of Interrupt Register
Section 4.16
8Ch
TCPPIIVECTR
Transmit CPPI DMA Controller Interrupt Vector Register
Section 4.17
90h
TCPPIMSKSR
Transmit CPPI Masked Status Register
Section 4.18
94h
TCPPIRAWSR
Transmit CPPI Raw Status Register
Section 4.19
98h
TCPPIIENSETR
Transmit CPPI Interrupt Enable Set Register
Section 4.20
9Ch
TCPPIIENCLRR
Transmit CPPI Interrupt Enable Clear Register
Section 4.21
C0h
RCPPICR
Receive CPPI Control Register
Section 4.22
D0h
RCPPIMSKSR
Receive CPPI Masked Status Register
Section 4.23
D4h
RCPPIRAWSR
Receive CPPI Raw Status Register
Section 4.24
D8h
RCPPIENSETR
Receive CPPI Interrupt Enable Set Register
Section 4.25
DCh
RCPPIIENCLRR
Receive CPPI Interrupt Enable Clear Register
Section 4.26
E0h
RBUFCNT0
Receive Buffer Count 0 Register
Section 4.27
E4h
RBUFCNT1
Receive Buffer Count 1 Register
Section 4.28
E8h
RBUFCNT2
Receive Buffer Count 2 Register
Section 4.29
ECh
RBUFCNT3
Receive Buffer Count 3 Register
Section 4.30
Transmit/Receive CPPI Channel 0 State Block
100h
TCPPIDMASTATEW0
Transmit CPPI DMA State Word 0
Section 4.31
104h
TCPPIDMASTATEW1
Transmit CPPI DMA State Word 1
Section 4.32
108h
TCPPIDMASTATEW2
Transmit CPPI DMA State Word 2
Section 4.33
10Ch
TCPPIDMASTATEW3
Transmit CPPI DMA State Word 3
Section 4.34
110h
TCPPIDMASTATEW4
Transmit CPPI DMA State Word 4
Section 4.35
114h
TCPPIDMASTATEW5
Transmit CPPI DMA State Word 5
Section 4.36
11Ch
TCPPICOMPPTR
Transmit CPPI Completion Pointer
Section 4.37
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Table 16. Universal Serial Bus (USB) Registers (continued)
Offset
Acronym
Register Description
120h
RCPPIDMASTATEW0
Receive CPPI DMA State Word 0
Section 4.38
Section
124h
RCPPIDMASTATEW1
Receive CPPI DMA State Word 1
Section 4.39
128h
RCPPIDMASTATEW2
Receive CPPI DMA State Word 2
Section 4.40
12Ch
RCPPIDMASTATEW3
Receive CPPI DMA State Word 3
Section 4.41
130h
RCPPIDMASTATEW4
Receive CPPI DMA State Word 4
Section 4.42
134h
RCPPIDMASTATEW5
Receive CPPI DMA State Word 5
Section 4.43
138h
RCPPIDMASTATEW6
Receive CPPI DMA State Word 6
Section 4.44
13Ch
RCPPICOMPPTR
Receive CPPI Completion Pointer
Section 4.45
Transmit/Receive CPPI Channel 1 State Block
140h
TCPPIDMASTATEW0
Transmit CPPI DMA State Word 0
Section 4.31
144h
TCPPIDMASTATEW1
Transmit CPPI DMA State Word 1
Section 4.32
148h
TCPPIDMASTATEW2
Transmit CPPI DMA State Word 2
Section 4.33
14Ch
TCPPIDMASTATEW3
Transmit CPPI DMA State Word 3
Section 4.34
150h
TCPPIDMASTATEW4
Transmit CPPI DMA State Word 4
Section 4.35
154h
TCPPIDMASTATEW5
Transmit CPPI DMA State Word 5
Section 4.36
15Ch
TCPPICOMPPTR
Transmit CPPI Completion Pointer
Section 4.37
160h
RCPPIDMASTATEW0
Receive CPPI DMA State Word 0
Section 4.38
164h
RCPPIDMASTATEW1
Receive CPPI DMA State Word 1
Section 4.39
168h
RCPPIDMASTATEW2
Receive CPPI DMA State Word 2
Section 4.40
16Ch
RCPPIDMASTATEW3
Receive CPPI DMA State Word 3
Section 4.41
170h
RCPPIDMASTATEW4
Receive CPPI DMA State Word 4
Section 4.42
174h
RCPPIDMASTATEW5
Receive CPPI DMA State Word 5
Section 4.43
178h
RCPPIDMASTATEW6
Receive CPPI DMA State Word 6
Section 4.44
17Ch
RCPPICOMPPTR
Receive CPPI Completion Pointer
Section 4.45
180h
TCPPIDMASTATEW0
Transmit CPPI DMA State Word 0
Section 4.31
184h
TCPPIDMASTATEW1
Transmit CPPI DMA State Word 1
Section 4.32
Transmit/Receive CPPI Channel 2 State Block
188h
TCPPIDMASTATEW2
Transmit CPPI DMA State Word 2
Section 4.33
18Ch
TCPPIDMASTATEW3
Transmit CPPI DMA State Word 3
Section 4.34
190h
TCPPIDMASTATEW4
Transmit CPPI DMA State Word 4
Section 4.35
194h
TCPPIDMASTATEW5
Transmit CPPI DMA State Word 5
Section 4.36
19Ch
TCPPICOMPPTR
Transmit CPPI Completion Pointer
Section 4.37
1A0h
RCPPIDMASTATEW0
Receive CPPI DMA State Word 0
Section 4.38
1A4h
RCPPIDMASTATEW1
Receive CPPI DMA State Word 1
Section 4.39
1A8h
RCPPIDMASTATEW2
Receive CPPI DMA State Word 2
Section 4.40
1ACh
RCPPIDMASTATEW3
Receive CPPI DMA State Word 3
Section 4.41
1B0h
RCPPIDMASTATEW4
Receive CPPI DMA State Word 4
Section 4.42
1B4h
RCPPIDMASTATEW5
Receive CPPI DMA State Word 5
Section 4.43
1B8h
RCPPIDMASTATEW6
Receive CPPI DMA State Word 6
Section 4.44
1BCh
RCPPICOMPPTR
Receive CPPI Completion Pointer
Section 4.45
Transmit/Receive CPPI Channel 3 State Block
74
1C0h
TCPPIDMASTATEW0
Transmit CPPI DMA State Word 0
Section 4.31
1C4h
TCPPIDMASTATEW1
Transmit CPPI DMA State Word 1
Section 4.32
1C8h
TCPPIDMASTATEW2
Transmit CPPI DMA State Word 2
Section 4.33
1CCh
TCPPIDMASTATEW3
Transmit CPPI DMA State Word 3
Section 4.34
1D0h
TCPPIDMASTATEW4
Transmit CPPI DMA State Word 4
Section 4.35
Universal Serial Bus (USB) Controller
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Table 16. Universal Serial Bus (USB) Registers (continued)
Offset
Acronym
Register Description
1D4h
TCPPIDMASTATEW5
Transmit CPPI DMA State Word 5
Section 4.36
Section
1DCh
TCPPICOMPPTR
Transmit CPPI Completion Pointer
Section 4.37
1E0h
RCPPIDMASTATEW0
Receive CPPI DMA State Word 0
Section 4.38
1E4h
RCPPIDMASTATEW1
Receive CPPI DMA State Word 1
Section 4.39
1E8h
RCPPIDMASTATEW2
Receive CPPI DMA State Word 2
Section 4.40
1ECh
RCPPIDMASTATEW3
Receive CPPI DMA State Word 3
Section 4.41
1F0h
RCPPIDMASTATEW4
Receive CPPI DMA State Word 4
Section 4.42
1F4h
RCPPIDMASTATEW5
Receive CPPI DMA State Word 5
Section 4.43
1F8h
RCPPIDMASTATEW6
Receive CPPI DMA State Word 6
Section 4.44
1FCh
RCPPICOMPPTR
Receive CPPI Completion Pointer
Section 4.45
Common USB Registers
400h
FADDR
Function Address Register
Section 4.46
401h
POWER
Power Management Register
Section 4.47
402h
INTRTX
Interrupt Register for Endpoint 0 plus Transmit Endpoints 1 to 4
Section 4.48
404h
INTRRX
Interrupt Register for Receive Endpoints 1 to 4
Section 4.49
406h
INTRTXE
Interrupt enable register for INTRTX
Section 4.50
408h
INTRRXE
Interrupt Enable Register for INTRRX
Section 4.51
40Ah
INTRUSB
Interrupt Register for Common USB Interrupts
Section 4.52
40Bh
INTRUSBE
Interrupt Enable Register for INTRUSB
Section 4.53
40Ch
FRAME
Frame Number Register
Section 4.54
40Eh
INDEX
Index Register for Selecting the Endpoint Status and Control
Registers
Section 4.55
40Fh
TESTMODE
Register to Enable the USB 2.0 Test Modes
Section 4.56
Indexed Registers
These registers operate on the endpoint selected by the INDEX register
410h
TXMAXP
Maximum Packet Size for Peripheral/Host Transmit Endpoint.
(Index register set to select Endpoints 1-4)
Section 4.57
412h
PERI_CSR0
Control Status Register for Endpoint 0 in Peripheral Mode.
(Index register set to select Endpoint 0)
Section 4.58
HOST_CSR0
Control Status Register for Endpoint 0 in Host Mode.
(Index register set to select Endpoint 0)
Section 4.59
PERI_TXCSR
Control Status Register for Peripheral Transmit Endpoint.
(Index register set to select Endpoints 1-4)
Section 4.60
HOST_TXCSR
Control Status Register for Host Transmit Endpoint.
(Index register set to select Endpoints 1-4)
Section 4.61
414h
RXMAXP
Maximum Packet Size for Peripheral/Host Receive Endpoint.
(Index register set to select Endpoints 1-4)
Section 4.62
416h
PERI_RXCSR
Control Status Register for Peripheral Receive Endpoint.
(Index register set to select Endpoints 1-4)
Section 4.63
HOST_RXCSR
Control Status Register for Host Receive Endpoint.
(Index register set to select Endpoints 1-4)
Section 4.64
COUNT0
Number of Received Bytes in Endpoint 0 FIFO.
(Index register set to select Endpoint 0)
Section 4.65
RXCOUNT
Number of Bytes in Host Receive Endpoint FIFO.
(Index register set to select Endpoints 1- 4)
Section 4.66
HOST_TYPE0
Defines the speed of Endpoint 0
Section 4.67
HOST_TXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Transmit endpoint.
(Index register set to select Endpoints 1-4)
Section 4.68
418h
41Ah
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Table 16. Universal Serial Bus (USB) Registers (continued)
Offset
Acronym
Register Description
41Bh
HOST_NAKLIMIT0
Sets the NAK response timeout on Endpoint 0.
(Index register set to select Endpoint 0)
Section 4.69
Section
HOST_TXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Transmit
endpoint. (Index register set to select Endpoints 1-4)
Section 4.70
41Ch
HOST_RXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Receive endpoint.
(Index register set to select Endpoints 1-4)
Section 4.71
41Dh
HOST_RXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Receive
endpoint. (Index register set to select Endpoints 1-4)
Section 4.72
41Fh
CONFIGDATA
Returns details of core configuration. (Index register set to select
Endpoint 0)
Section 4.73
420h
FIFO0
Transmit and Receive FIFO Register for Endpoint 0
Section 4.74
424h
FIFO1
Transmit and Receive FIFO Register for Endpoint 1
Section 4.75
428h
FIFO2
Transmit and Receive FIFO Register for Endpoint 2
Section 4.76
42Ch
FIFO3
Transmit and Receive FIFO Register for Endpoint 3
Section 4.77
430h
FIFO4
Transmit and Receive FIFO Register for Endpoint 4
Section 4.78
460h
DEVCTL
OTG Device Control Register
FIFOn
OTG Device Control
Section 4.79
Dynamic FIFO Control
462h
TXFIFOSZ
Transmit Endpoint FIFO Size
(Index register set to select Endpoints 1-4)
Section 4.80
463h
RXFIFOSZ
Receive Endpoint FIFO Size
(Index register set to select Endpoints 1-4)
Section 4.81
464h
TXFIFOADDR
Transmit Endpoint FIFO Address
(Index register set to select Endpoints 1-4)
Section 4.82
466h
RXFIFOADDR
Receive Endpoint FIFO Address
(Index register set to select Endpoints 1-4)
Section 4.83
480h
TXFUNCADDR
Address of the target function that has to be accessed through
the associated Transmit Endpoint.
Section 4.84
482h
TXHUBADDR
Address of the hub that has to be accessed through the
associated Transmit Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.85
483h
TXHUBPORT
Port of the hub that has to be accessed through the associated
Transmit Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.86
484h
RXFUNCADDR
Address of the target function that has to be accessed through
the associated Receive Endpoint.
Section 4.87
486h
RXHUBADDR
Address of the hub that has to be accessed through the
associated Receive Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.88
487h
RXHUBPORT
Port of the hub that has to be accessed through the associated
Receive Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.89
Target Endpoint 0 Control Registers, Valid Only in Host Mode
Target Endpoint 1 Control Registers, Valid Only in Host Mode
76
488h
TXFUNCADDR
Address of the target function that has to be accessed through
the associated Transmit Endpoint.
Section 4.84
48Ah
TXHUBADDR
Address of the hub that has to be accessed through the
associated Transmit Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.85
Universal Serial Bus (USB) Controller
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Table 16. Universal Serial Bus (USB) Registers (continued)
Offset
Acronym
Register Description
48Bh
TXHUBPORT
Port of the hub that has to be accessed through the associated
Transmit Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.86
Section
48Ch
RXFUNCADDR
Address of the target function that has to be accessed through
the associated Receive Endpoint.
Section 4.87
48Eh
RXHUBADDR
Address of the hub that has to be accessed through the
associated Receive Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.88
48Fh
RXHUBPORT
Port of the hub that has to be accessed through the associated
Receive Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.89
Target Endpoint 2 Control Registers, Valid Only in Host Mode
490h
TXFUNCADDR
Address of the target function that has to be accessed through
the associated Transmit Endpoint.
Section 4.84
492h
TXHUBADDR
Address of the hub that has to be accessed through the
associated Transmit Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.85
493h
TXHUBPORT
Port of the hub that has to be accessed through the associated
Transmit Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.86
494h
RXFUNCADDR
Address of the target function that has to be accessed through
the associated Receive Endpoint.
Section 4.87
496h
RXHUBADDR
Address of the hub that has to be accessed through the
associated Receive Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.88
497h
RXHUBPORT
Port of the hub that has to be accessed through the associated
Receive Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.89
498h
TXFUNCADDR
Address of the target function that has to be accessed through
the associated Transmit Endpoint.
Section 4.84
49Ah
TXHUBADDR
Address of the hub that has to be accessed through the
associated Transmit Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.85
49Bh
TXHUBPORT
Port of the hub that has to be accessed through the associated
Transmit Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.86
49Ch
RXFUNCADDR
Address of the target function that has to be accessed through
the associated Receive Endpoint.
Section 4.87
49Eh
RXHUBADDR
Address of the hub that has to be accessed through the
associated Receive Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.88
49Fh
RXHUBPORT
Port of the hub that has to be accessed through the associated
Receive Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.89
4A0h
TXFUNCADDR
Address of the target function that has to be accessed through
the associated Transmit Endpoint.
Section 4.84
4A2h
TXHUBADDR
Address of the hub that has to be accessed through the
associated Transmit Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.85
4A3h
TXHUBPORT
Port of the hub that has to be accessed through the associated
Transmit Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.86
4A4h
RXFUNCADDR
Address of the target function that has to be accessed through
the associated Receive Endpoint.
Section 4.87
Target Endpoint 3 Control Registers, Valid Only in Host Mode
Target Endpoint 4 Control Registers, Valid Only in Host Mode
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Table 16. Universal Serial Bus (USB) Registers (continued)
Offset
Acronym
Register Description
4A6h
RXHUBADDR
Address of the hub that has to be accessed through the
associated Receive Endpoint. This is used only when full speed
or low speed device is connected via a USB2.0 high-speed hub.
Section 4.88
Section
4A7h
RXHUBPORT
Port of the hub that has to be accessed through the associated
Receive Endpoint. This is used only when full speed or low
speed device is connected via a USB2.0 high-speed hub.
Section 4.89
502h
PERI_CSR0
Control Status Register for Endpoint 0 in Peripheral Mode
Section 4.58
Control and Status Register for Endpoint 0
HOST_CSR0
Control Status Register for Endpoint 0 in Host Mode
Section 4.59
508h
COUNT0
Number of Received Bytes in Endpoint 0 FIFO
Section 4.65
50Ah
HOST_TYPE0
Defines the Speed of Endpoint 0
Section 4.67
50Bh
HOST_NAKLIMIT0
Sets the NAK Response Timeout on Endpoint 0
Section 4.69
50Fh
CONFIGDATA
Returns details of core configuration.
Section 4.73
Control and Status Register for Endpoint 1
510h
TXMAXP
Maximum Packet Size for Peripheral/Host Transmit Endpoint
Section 4.57
512h
PERI_TXCSR
Control Status Register for Peripheral Transmit Endpoint
(peripheral mode)
Section 4.60
HOST_TXCSR
Control Status Register for Host Transmit Endpoint
(host mode)
Section 4.61
514h
RXMAXP
Maximum Packet Size for Peripheral/Host Receive Endpoint
Section 4.62
516h
PERI_RXCSR
Control Status Register for Peripheral Receive Endpoint
(peripheral mode)
Section 4.63
HOST_RXCSR
Control Status Register for Host Receive Endpoint
(host mode)
Section 4.64
518h
RXCOUNT
Number of Bytes in Host Receive endpoint FIFO
Section 4.66
51Ah
HOST_TXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Transmit endpoint.
Section 4.68
51Bh
HOST_TXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Transmit
endpoint.
Section 4.70
51Ch
HOST_RXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Receive endpoint.
Section 4.71
51Dh
HOST_RXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Receive
endpoint.
Section 4.72
Control and Status Register for Endpoint 2
78
520h
TXMAXP
Maximum Packet Size for Peripheral/Host Transmit Endpoint
Section 4.57
522h
PERI_TXCSR
Control Status Register for Peripheral Transmit Endpoint
(peripheral mode)
Section 4.60
HOST_TXCSR
Control Status Register for Host Transmit Endpoint
(host mode)
Section 4.61
524h
RXMAXP
Maximum Packet Size for Peripheral/Host Receive Endpoint
Section 4.62
526h
PERI_RXCSR
Control Status Register for Peripheral Receive Endpoint
(peripheral mode)
Section 4.63
HOST_RXCSR
Control Status Register for Host Receive Endpoint
(host mode)
Section 4.64
528h
RXCOUNT
Number of Bytes in Host Receive endpoint FIFO
Section 4.66
52Ah
HOST_TXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Transmit endpoint.
Section 4.68
52Bh
HOST_TXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Transmit
endpoint.
Section 4.70
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Table 16. Universal Serial Bus (USB) Registers (continued)
Offset
Acronym
Register Description
52Ch
HOST_RXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Receive endpoint.
Section 4.71
Section
52Dh
HOST_RXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Receive
endpoint.
Section 4.72
530h
TXMAXP
Maximum Packet Size for Peripheral/Host Transmit Endpoint
Section 4.57
532h
PERI_TXCSR
Control Status Register for Peripheral Transmit Endpoint
(peripheral mode)
Section 4.60
HOST_TXCSR
Control Status Register for Host Transmit Endpoint
(host mode)
Section 4.61
534h
RXMAXP
Maximum Packet Size for Peripheral/Host Receive Endpoint
Section 4.62
536h
PERI_RXCSR
Control Status Register for Peripheral Receive Endpoint
(peripheral mode)
Section 4.63
HOST_RXCSR
Control Status Register for Host Receive Endpoint
(host mode)
Section 4.64
Control and Status Register for Endpoint 3
538h
RXCOUNT
Number of Bytes in Host Receive endpoint FIFO
Section 4.66
53Ah
HOST_TXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Transmit endpoint.
Section 4.68
53Bh
HOST_TXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Transmit
endpoint.
Section 4.70
53Ch
HOST_RXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Receive endpoint.
Section 4.71
53Dh
HOST_RXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Receive
endpoint.
Section 4.72
540h
TXMAXP
Maximum Packet Size for Peripheral/Host Transmit Endpoint
Section 4.57
542h
PERI_TXCSR
Control Status Register for Peripheral Transmit Endpoint
(peripheral mode)
Section 4.60
HOST_TXCSR
Control Status Register for Host Transmit Endpoint
(host mode)
Section 4.61
544h
RXMAXP
Maximum Packet Size for Peripheral/Host Receive Endpoint
Section 4.62
546h
PERI_RXCSR
Control Status Register for Peripheral Receive Endpoint
(peripheral mode)
Section 4.63
HOST_RXCSR
Control Status Register for Host Receive Endpoint
(host mode)
Section 4.64
Control and Status Register for Endpoint 4
548h
RXCOUNT
Number of Bytes in Host Receive endpoint FIFO
Section 4.66
54Ah
HOST_TXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Transmit endpoint.
Section 4.68
54Bh
HOST_TXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Transmit
endpoint.
Section 4.70
54Ch
HOST_RXTYPE
Sets the operating speed, transaction protocol and peripheral
endpoint number for the host Receive endpoint.
Section 4.71
54Dh
HOST_RXINTERVAL
Sets the polling interval for Interrupt/ISOC transactions or the
NAK response timeout on Bulk transactions for host Receive
endpoint.
Section 4.72
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Control Register (CTRLR)
The Control Register (CTRLR) is shown in Figure 16 and described in Table 17.
Figure 16. Control Register (CTRLR)
31
16
Reserved
R-0
15
4
3
2
1
0
Reserved
5
RNDIS
UINT
Reserved
CLKFACK
RESET
R-0
R/W-0
R/W-0
R-0
R/W-0
W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 17. Control Register (CTRLR) Field Descriptions
Bit
31-5
Field
Reserved
Value
0
Description
Reserved
4
RNDIS
0-1
RNDIS mode enable.
3
UINT
0-1
USB non-PDR interrupt enable.
2
Reserved
0
1
CLKFACK
0-1
0
RESET
Reserved
Clock stop fast ACK enable.
Soft reset.
0
1
4.2
Writing a 1 starts a module reset.
Status Register (STATR)
The Status Register (STATR) is shown in Figure 17 and described in Table 18.
Figure 17. Status Register (STATR)
31
16
Reserved
R-0
15
1
0
Reserved
DRVVBUS
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 18. Status Register (STATR) Field Descriptions
Bit
80
Field
31-1
Reserved
0
DRVVBUS
Value
0
Description
Reserved
Current DRVVBUS value.
0
DRVVBUS value is logic 0
1
DRVVBUS value is logic 1
Universal Serial Bus (USB) Controller
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4.3
RNDIS Register (RNDISR)
The RNDIS Register (RNDISR) is shown in Figure 18 and described in Table 19.
Figure 18. RNDIS Register (RNDISR)
31
20
19
18
17
16
Reserved
RX4EN
RX3EN
RX2EN
RX1EN
R-0
R/W-0
R/W-0
R/W-0
R/W-0
15
3
2
1
0
Reserved
4
TX4EN
TX3EN
TX2EN
TX1EN
R-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 19. RNDIS Register (RNDISR) Field Descriptions
Bit
31-20
Field
Reserved
Value
0
Description
Reserved
19
RX4EN
0-1
Receive Endpoint 4 RNDIS mode enable.
18
RX3EN
0-1
Receive Endpoint 3 RNDIS mode enable.
17
RX2EN
0-1
Receive Endpoint 2 RNDIS mode enable.
16
RX1EN
0-1
Receive Endpoint 1 RNDIS mode enable.
15-4
Reserved
0
Reserved
3
TX4EN
0-1
Transmit Endpoint 4 RNDIS mode enable.
2
TX3EN
0-1
Transmit Endpoint 3 RNDIS mode enable.
1
TX2EN
0-1
Transmit Endpoint 2 RNDIS mode enable.
0
TX1EN
0-1
Transmit Endpoint 1 RNDIS mode enable.
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Auto Request Register (AUTOREQ)
The Auto Request Register (AUTOREQ) is shown in Figure 19 and described in Table 20.
Figure 19. Auto Request Register (AUTOREQ)
31
16
Reserved
R-0
15
8
7
6
5
4
3
2
1
0
Reserved
Rx4
Rx3
Rx2
Rx1
R-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 20. Auto Request Register (AUTOREQ) Field Descriptions
Bit
Reserved
7-6
Rx4
5-4
3-2
1-0
82
Field
31-8
Rx3
Rx2
Rx1
Value
0
0-3h
Description
Reserved
RX endpoint 4 Auto Req enable.
0
No auto req
1
Auto req on all but EOP
2h
Reserved
3h
Auto req always
0-3h
RX endpoint 3 Auto Req enable.
0
No auto req
1
Auto req on all but EOP
2h
Reserved
3h
Auto req always
0-3h
RX endpoint 2 Auto Req enable.
0
No auto req
1
Auto req on all but EOP
2h
Reserved
3h
Auto req always
0-3h
RX endpoint 1 Auto Req enable.
0
No auto req
1
Auto req on all but EOP
2h
Reserved
3h
Auto req always
Universal Serial Bus (USB) Controller
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4.5
USB Interrupt Source Register (INTSRCR)
The USB Interrupt Source Register (INTSRCR) is shown in Figure 20 and described in Table 21.
Figure 20. USB Interrupt Source Register (INTSRCR)
31
25
15
24
16
Reserved
USB
R-0
R-0
13
12
8
7
5
4
0
Reserved
RX
Reserved
TX
R-0
R-0
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 21. USB Interrupt Source Register (INTSRCR) Field Descriptions
Bit
Field
31-25
Reserved
24-16
USB
15-13
Reserved
12-8
RX
7-5
Reserved
4-0
TX
Value
0
Description
Reserved
0-1FFh USB interrupt sources
Generated by the USB core (not the DMA)
0
0-1Fh
Reserved
Receive endpoint interrupt sources
Generated by the USB core (not the DMA)
0
0-Fh
Reserved
Transmit endpoint interrupt sources
Generated by the USB core (not the DMA)
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USB Interrupt Source Set Register (INTSETR)
The USB Interrupt Source Set Register (INTSETR) is shown in Figure 21 and described in Table 22.
Figure 21. USB Interrupt Source Set Register (INTSETR)
31
25
15
24
16
Reserved
USB
R-0
W-0
13
12
8
7
5
4
0
Reserved
RX
Reserved
TX
R-0
W-0
R-0
W-0
LEGEND: R = Read only; W = Write only; -n = value after reset
Table 22. USB Interrupt Source Set Register (INTSETR) Field Descriptions
Bit
Field
31-25
Reserved
24-16
USB
15-13
Reserved
12-8
RX
7-5
Reserved
4-0
TX
Value
0
Description
Reserved
0-1FFh Write a 1 to set equivalent USB interrupt source
Allows the USB interrupt sources to be manually triggered
0
0-1Fh
Reserved
Write a 1 to set equivalent Receive endpoint interrupt source
Allows the USB interrupt sources to be manually triggered
0
0-Fh
Reserved
Write a 1 to set equivalent Transmit endpoint interrupt source
Allows the USB interrupt sources to be manually triggered
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4.7
USB Interrupt Source Clear Register (INTCLRR)
The USB Interrupt Source Clear Register (INTCLRR) is shown in Figure 22 and described in Table 23.
Figure 22. USB Interrupt Source Clear Register (INTCLRR)
31
25
15
24
16
Reserved
USB
R-0
W-0
13
12
8
7
5
4
0
Reserved
RX
Reserved
TX
R-0
W-0
R-0
W-0
LEGEND: R = Read only; W = Write only; -n = value after reset
Table 23. USB Interrupt Source Clear Register (INTCLRR) Field Descriptions
Bit
Field
31-25
Reserved
24-16
USB
15-13
Reserved
12-8
RX
7-5
Reserved
4-0
TX
Value
0
Description
Reserved
0-1FFh Write a 1 to clear equivalent USB interrupt source
Allows the CPU to acknowledge an interrupt source and turn it off
0
0-1Fh
Reserved
Write a 1 to clear equivalent Receive endpoint interrupt source
Allows the CPU to acknowledge an interrupt source and turn it off
0
0-Fh
Reserved
Write a 1 to clear equivalent Transmit endpoint interrupt source
Allows the CPU to acknowledge an interrupt source and turn it off
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USB Interrupt Mask Register (INTMSKR)
The USB Interrupt Mask Register (INTMSKR) is shown in Figure 23 and described in Table 24.
Figure 23. USB Interrupt Mask Register (INTMSKR)
31
25
15
24
16
Reserved
USB
R-0
R-0
13
12
8
7
5
4
0
Reserved
RX
Reserved
TX
R-0
R-0
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 24. USB Interrupt Mask Register (INTMSKR) Field Descriptions
Bit
Field
31-25
Reserved
24-16
USB
Value
0
Description
Reserved
0-1FFh USB interrupt source masks
Contains the masks of the interrupt sources generated by the USB core (not the DMA). These
masks are used to enable or disable interrupt sources appearing as masked interrupts
15-13
Reserved
12-8
RX
0
1Fh
Reserved
Receive endpoint interrupt source masks
Contains the masks of the interrupt sources generated by the USB core (not the DMA). These
masks are used to enable or disable interrupt sources appearing as masked interrupts.
7-5
Reserved
4-0
TX
0
0-Fh
Reserved
Transmit endpoint interrupt source masks
Contains the masks of the interrupt sources generated by the USB core (not the DMA). These
masks are used to enable or disable interrupt sources appearing as masked interrupts.
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4.9
USB Interrupt Mask Set Register (INTMSKSETR)
The USB Interrupt Mask Set Register (INTMSKSETR) is shown in Figure 24 and described in Table 25.
Figure 24. USB Interrupt Mask Set Register (INTMSKSETR)
31
25
15
24
16
Reserved
USB
R-0
W-0
13
12
8
7
5
4
0
Reserved
RX
Reserved
TX
R-0
W-0
R-0
W-0
LEGEND: R = Read only; W = Write only; -n = value after reset
Table 25. USB Interrupt Mask Set Register (INTMSKSETR) Field Descriptions
Bit
Field
31-25
Reserved
24-16
USB
15-13
Reserved
12-8
RX
7-5
Reserved
4-0
TX
Value
0
Description
Reserved
0-1FFh Write a 1 to set equivalent USB interrupt mask
Allows the USB interrupt masks to be individually enabled
0
0-1Fh
Reserved
Write a 1 to set equivalent Receive endpoint interrupt mask
Allows the USB interrupt masks to be individually enabled
0
0-Fh
Reserved
Write a 1 to set equivalent Transmit endpoint interrupt mask
Allows the USB interrupt masks to be individually enabled
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4.10 USB Interrupt Mask Clear Register (INTMSKCLRR)
The USB Interrupt Mask Clear Register (INTMSKCLRR) is shown in Figure 25 and described in Table 26.
Figure 25. USB Interrupt Mask Clear Register (INTMSKCLRR)
31
25
15
24
16
Reserved
USB
R-0
W-0
13
12
8
7
5
4
0
Reserved
RX
Reserved
TX
R-0
W-0
R-0
W-0
LEGEND: R = Read only; W = Write only; -n = value after reset
Table 26. USB Interrupt Mask Clear Register (INTMSKCLRR) Field Descriptions
Bit
Field
31-25
Reserved
24-16
USB
15-13
Reserved
12-8
RX
7-5
Reserved
4-0
TX
Value
0
Description
Reserved
0-1FFh Write a 1 to clear equivalent USB interrupt mask
Allows the USB interrupt masks to be individually disabled
0
0-1Fh
Reserved
Write a 1 to clear equivalent Receive endpoint interrupt mask
Allows the USB interrupt masks to be individually disabled
0
0-Fh
Reserved
Write a 1 to clear equivalent Transmit endpoint interrupt mask
Allows the USB interrupt masks to be individually disabled
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4.11 USB Interrupt Source Masked Register (INTMASKEDR)
The USB Interrupt Source Masked Register (INTMASKEDR) is shown in Figure 26 and described in
Table 27.
Figure 26. USB Interrupt Source Masked Register (INTMASKEDR)
31
25
15
24
16
Reserved
USB
R-0
R-0
13
12
8
7
5
4
0
Reserved
RX
Reserved
TX
R-0
R-0
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 27. USB Interrupt Source Masked Register (INTMASKEDR) Field Descriptions
Bit
Field
31-25
Reserved
24-16
USB
Value
0
Description
Reserved
0-1FFh USB interrupt sources masked
Contains the status of the interrupt sources generated by the USB core masked by the USB
Interrupt Mask Register values
15-13
Reserved
12-8
RX
0
0-1Fh
Reserved
Receive endpoint interrupt sources masked
Contains the status of the interrupt sources generated by the USB core masked by the USB
Interrupt Mask Register values.
7-5
Reserved
4-0
TX
0
0-Fh
Reserved
Transmit endpoint interrupt sources masked
Contains the status of the interrupt sources generated by the USB core masked by the USB
Interrupt Mask Register values.
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4.12 USB End of Interrupt Register (EOIR)
The USB End of Interrupt Register (EOIR) is shown in Figure 27 and described in Table 28.
Figure 27. USB End of Interrupt Register (EOIR)
31
16
Reserved
R-0
15
8
7
0
Reserved
VECTOR
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 28. USB End of Interrupt Register (EOIR) Field Descriptions
Bit
Field
Value
31-8
Reserved
0
7-0
VECTOR
0-FFh
Description
Reserved
EOI Vector
Allows the CPU to acknowledge completion of an interrupt by writing to the EOI. An eoi_write signal
will be generated, the EOI vector will be updated to the written value, and another interrupt will be
triggered if interrupt sources remain.
4.13 USB Interrupt Vector Register (INTVECTR)
The USB Interrupt Vector Register (INTVECTR) is shown in Figure 28 and described in Table 29.
Figure 28. USB Interrupt Vector Register (INTVECTR)
31
0
VECTOR
R-0
LEGEND: R = Read only; -n = value after reset
Table 29. USB Interrupt Vector Register (INTVECTR) Field Descriptions
Bit
31-0
Field
VECTOR
Value
0-FFFF FFFFh
Description
Input Interrupt Vector
Recycles the Interrupt Vector input to be read by the CPU
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4.14 Transmit CPPI Control Register (TCPPICR)
The Transmit CPPI Control Register (TCPPICR) is shown in Figure 29 and described in Table 30.
Figure 29. Transmit CPPI Control Register (TCPPICR)
31
16
Reserved
R-0
15
1
0
Reserved
TCPPI_ENABLE
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 30. Transmit CPPI Control Register (TCPPICR) Field Descriptions
Bit
Field
31-1
Value
Reserved
0
0
Description
Reserved
TCPPI_ENABLE
Transmit CPPI Enable Controls if the Transmit CPPI DMA controller is enabled
0
Transmit CPPI DMA is disabled
1
Transmit CPPI DMA is enabled
4.15 Transmit CPPI Teardown Register (TCPPITDR)
The Transmit CPPI Teardown Register (TCPPITDR) is shown in Figure 30 and described in Table 31.
Figure 30. Transmit CPPI Teardown Register (TCPPITDR)
31
30
16
READY
Reserved
R-1
R-0
15
2
1
0
Reserved
CHANNEL
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 31. Transmit CPPI Teardown Register (TCPPITDR) Field Descriptions
Bit
Field
31
READY
Value
0-1
30-2
Reserved
0
1-0
CHANNEL
0-3h
Description
Indicates if the Teardown register can be written
Reserved
Teardown Channel
Indicates the channel that is to be torn down
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4.16 Transmit CPPI DMA Controller End of Interrupt Register (TCPPIEOIR)
The Transmit CPPI DMA Controller End of Interrupt Register (TCPPIEOIR) is shown in Figure 31 and
described in Table 32.
Figure 31. Transmit CPPI DMA Controller End of Interrupt Register (TCPPIEOIR)
31
16
Reserved
R-0
15
8
7
0
Reserved
VECTOR
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 32. Transmit CPPI DMA Controller End of Interrupt Register (TCPPIEOIR) Field Descriptions
Bit
Field
Value
31-8
Reserved
0
7-0
VECTOR
0-FFh
Description
Reserved
End of Interrupt Vector
This is an application specific register which is essentially a general purpose output from the
LCSAR. One cycle after this register is written, the eoi_vector[7:0] value will appear on the
eoi_vector output port from the LCSAR and the eoi_write output port will be asserted for 1 clock
cycle. This register is used to convert level sensitive interrupts to pulsed, non-redundant interrupts.
4.17 Transmit CPPI DMA Controller Interrupt Vector Register (TCPPIIVECTR)
The Transmit CPPI DMA Controller Interrupt Vector Register (TCPPIIVECTR) is shown in Figure 32 and
described in Table 33.
Figure 32. Transmit CPPI DMA Controller Interrupt Vector Register (TCPPIIVECTR)
31
0
VECTOR
R-0
LEGEND: R = Read only; -n = value after reset
Table 33. Transmit CPPI DMA Controller Interrupt Vector Register (TCPPIIVECTR)
Field Descriptions
Bit
31-0
Field
VECTOR
Value
0-FFFF FFFFh
Description
Interrupt Vector
This is an application specific register, which is essentially a general purpose input to the
LCSAR. The intr_vector field in this register is a registered version of the intr_vector primary
input to the LCSAR. This register is used for interrupt handling.
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4.18 Transmit CPPI Masked Status Register (TCPPIMSKSR)
The Transmit CPPI Masked Status Register (TCPPIMSKSR) is shown in Figure 33 and described in
Table 34.
Figure 33. Transmit CPPI Masked Status Register (TCPPIMSKSR)
31
16
Reserved
R-0
15
4
3
0
Reserved
MASKED COMP_PENDING
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 34. Transmit CPPI Masked Status Register (TCPPIMSKSR) Field Descriptions
Bit
Field
Value Description
31-4
Reserved
0
3-0
MASKED COMP_PENDING
0-Fh
Reserved
Masked High Priority Transmit Completion Pending
Indicators for channels 3 to 0 Raw Transmit high priority completion indicators bitwise
ANDed with Transmit high priority completion mask bits
4.19 Transmit CPPI Raw Status Register (TCPPIRAWSR)
The Transmit CPPI Raw Status Register (TCPPIRAWSR) is shown in Figure 34 and described in
Table 35.
Figure 34. Transmit CPPI Raw Status Register (TCPPIRAWSR)
31
16
Reserved
R-0
15
4
3
0
Reserved
COMP_PENDING
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 35. Transmit CPPI Raw Status Register (TCPPIRAWSR) Field Descriptions
Bit
Field
31-4
Reserved
3-0
COMP_PENDING
Value
0
0-Fh
Description
Reserved
Raw High Priority Transmit Completion Pending
Indicators for channels 3 to 0 Active high flags which indicate that a packet has completed
transmission on the high priority queue
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4.20 Transmit CPPI Interrupt Enable Set Register (TCPPIIENSETR)
The Transmit CPPI Interrupt Enable Set Register (TCPPIIENSETR) is shown in Figure 35 and described
in Table 36.
Figure 35. Transmit CPPI Interrupt Enable Set Register (TCPPIIENSETR)
31
16
Reserved
R-0
15
4
3
0
Reserved
COMP_PENDING_INTR_EN
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 36. Transmit CPPI Interrupt Enable Set Register (TCPPIIENSETR) Field Descriptions
Bit
Field
Value Description
31-4
Reserved
0
3-0
COMP_PENDING_INTR_EN
0-Fh
Reserved
Transmit CPPI High Priority Interrupt Enables
These are active high interrupt enables corresponding to the Transmit CPPI High
Priority Completion Pending status bits.
4.21 Transmit CPPI Interrupt Enable Clear Register (TCPPIIENCLRR)
The Transmit CPPI Interrupt Enable Clear Register (TCPPIIENCLRR) is shown in Figure 36 and
described in Table 37.
Figure 36. Transmit CPPI Interrupt Enable Clear Register (TCPPIIENCLRR)
31
16
Reserved
R-0
15
4
3
0
Reserved
COMP_PENDING_INTR_EN
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 37. Transmit CPPI Interrupt Enable Clear Register (TCPPIIENCLRR) Field Descriptions
Bit
Field
31-4
Reserved
3-0
COMP_PENDING_INTR_EN
94
Value Description
0
0-Fh
Universal Serial Bus (USB) Controller
Reserved
Writing a 1 to any of the bits in the Transmit CPPI Interrupt Enable Clear Register will
result in clearing of the corresponding bit in the Transmit CPPI High Priority Interrupt
Enable Register.
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4.22 Receive CPPI Control Register (RCPPICR)
The Receive CPPI Control Register (RCPPICR) is shown in Figure 37 and described in Table 38.
Figure 37. Receive CPPI Control Register (RCPPICR)
31
16
Reserved
R-0
15
1
0
Reserved
RCPPI_ENABLE
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 38. Receive CPPI Control Register (RCPPICR) Field Descriptions
Bit
31-1
0
Field
Value
Reserved
0
RCPPI_ENABLE
Description
Reserved
Receive CPPI Enable Controls if the Receive CPPI DMA controller is enabled.
0
Receive CPPI DMA is disabled.
1
Receive CPPI DMA is enabled.
4.23 Receive CPPI Masked Status Register (RCPPIMSKSR)
The Receive CPPI Masked Status Register (RCPPIMSKSR) is shown in Figure 38 and described in
Table 39.
Figure 38. Receive CPPI Masked Status Register (RCPPIMSKSR)
31
16
Reserved
R-0
15
4
3
0
Reserved
MASKED_COMP_PENDING
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 39. Receive CPPI Masked Status Register (RCPPIMSKSR) Field Descriptions
Bit
Field
31-4
Reserved
3-0
MASKED_COMP_PENDING
Value
0
0-Fh
Description
Reserved
Masked Receive Completion Pending
Indicators for channels 3 to 0 Raw Receive completion indicators bitwise ANDed with
Receive completion mask bits
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4.24 Receive CPPI Raw Status Register (RCPPIRAWSR)
The Receive CPPI Raw Status Register (RCPPIRAWSR) is shown in Figure 39 and described in
Table 40.
Figure 39. Receive CPPI Raw Status Register (RCPPIRAWSR)
31
16
Reserved
R-0
15
4
3
0
Reserved
COMP_PENDING
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 40. Receive CPPI Raw Status Register (RCPPIRAWSR) Field Descriptions
Bit
Field
Value
31-4
Reserved
0
3-0
COMP_PENDING
0-Fh
Description
Reserved
Raw Receive Completion Pending
Indicators for channels 3 to 0 Active high flags which indicate that a packet has completed
reception
4.25 Receive CPPI Interrupt Enable Set Register (RCPPIENSETR)
The Receive CPPI Interrupt Enable Set Register (RCPPIENSETR) is shown in Figure 40 and described in
Table 41.
Figure 40. Receive CPPI Interrupt Enable Set Register (RCPPIENSETR)
31
16
Reserved
R-0
15
4
3
0
Reserved
COMP_PENDING_INTR_EN
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 41. Receive CPPI Interrupt Enable Set Register (RCPPIENSETR) Field Descriptions
Bit
Field
31-4
Reserved
3-0
COMP_PENDING_INTR_EN
Value
0
0-Fh
Description
Reserved
Receive CPPI Interrupt Enables
These are active high interrupt enables corresponding to the Receive CPPI Completion
Pending status bits. Writing a 1 to any of the bits in the Receive CPPI Interrupt Enable
Set Register will result in setting of the corresponding bit in the Receive CPPI Interrupt
Enable Register.
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4.26 Receive CPPI Interrupt Enable Clear Register (RCPPIIENCLRR)
The Receive CPPI Interrupt Enable Clear Register (RCPPIIENCLRR) is shown in Figure 41 and described
in Table 42.
Figure 41. Receive CPPI Interrupt Enable Clear Register (RCPPIIENCLRR)
31
16
Reserved
R-0
15
4
3
0
Reserved
COMP_PENDING_INTR_EN
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 42. Receive CPPI Interrupt Enable Clear Register (RCPPIIENCLRR) Field Descriptions
Bit
Field
Value
31-4
Reserved
0
3-0
COMP_PENDING_INTR_EN
0-Fh
Description
Reserved
Receive CPPI Interrupt Enables
These are active high interrupt enables corresponding to the Receive CPPI
Completion Pending status bits. Writing a 1 to any of the bits in the Receive CPPI
Interrupt Enable Clear Register will result in clearing of the corresponding bit in the
Receive CPPI Interrupt Enable Register.
4.27 Receive Buffer Count 0 Register (RBUFCNT0)
The Receive Buffer Count 0 Register (RBUFCNT0) is shown in Figure 42 and described in Table 43.
Figure 42. Receive Buffer Count 0 Register (RBUFCNT0)
31
16
Reserved
R-0
15
0
BUFCNT
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 43. Receive Buffer Count 0 Register (RBUFCNT0) Field Descriptions
Bit
Field
Value
31-16
Reserved
0
15-0
BUFCNT
0-FFFFh
Description
Reserved
Receive CPPI Buffer Count
The current count of CPPI buffers in Receive channel 0 queue. Writes add to current value
(not overwrite).
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4.28 Receive Buffer Count 1 Register (RBUFCNT1)
The Receive Buffer Count 1 Register (RBUFCNT1) is shown in Figure 43 and described in Table 44.
Figure 43. Receive Buffer Count 1 Register (RBUFCNT1)
31
16
Reserved
R-0
15
0
BUFCNT
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 44. Receive Buffer Count 1 Register (RBUFCNT1) Field Descriptions
Bit
Field
Value
31-16
Reserved
0
15-0
BUFCNT
0-FFFFh
Description
Reserved
Receive CPPI Buffer Count
The current count of CPPI buffers in Receive channel 1queue. Writes add to current value
(not overwrite).
4.29 Receive Buffer Count 2 Register (RBUFCNT2)
The Receive Buffer Count 2 Register (RBUFCNT2) is shown in Figure 44 and described in Table 45.
Figure 44. Receive Buffer Count 2 Register (RBUFCNT2)
31
16
Reserved
R-0
15
0
BUFCNT
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 45. Receive Buffer Count 2 Register (RBUFCNT2) Field Descriptions
Bit
Field
Value
31-16
Reserved
0
15-0
BUFCNT
0-FFFFh
Description
Reserved
Receive CPPI Buffer Count
The current count of CPPI buffers in Receive channel 2 queue. Writes add to current value
(not overwrite).
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4.30 Receive Buffer Count 3 Register (RBUFCNT3)
The Receive Buffer Count 3 Register (RBUFCNT3) is shown in Figure 45 and described in Table 46.
Figure 45. Receive Buffer Count 3 Register (RBUFCNT3)
31
16
Reserved
R-0
15
0
BUFCNT
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 46. Receive Buffer Count 3 Register (RBUFCNT3) Field Descriptions
Bit
Field
Value
31-16
Reserved
0
15-0
BUFCNT
0-FFFFh
Description
Reserved
Receive CPPI Buffer Count 0
The current count of CPPI buffers in Receive channel 3 queue. Writes add to current value
(not overwrite).
4.31 Transmit CPPI DMA State Word 0 (TCPPIDMASTATEW0)
The Transmit CPPI DMA State Word 0 (TCPPIDMASTATEW0) is shown in Figure 46 and described in
Table 47.
Figure 46. Transmit CPPI DMA State Word 0 (TCPPIDMASTATEW0)
31
16
TXQ_HEAD_PTR
R/W-0
15
2
1
0
TXQ_HEAD_PTR
Reserved
IN_PACKET
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 47. Transmit CPPI DMA State Word 0 (TCPPIDMASTATEW0) Field Descriptions
Bit
31-2
Field
TXQ_HEAD_PTR
Value
0-3FFF FFFFh
Description
TX Queue Head Pointer
30 bit pointer to 32-bit aligned descriptor at the head of the high priority TX queue
1
Reserved
0
IN_PACKET
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0
Reserved
Flag indicating the DMA is in the middle of processing a packet
0
Not currently in packet
1
Currently in packet
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4.32 Transmit CPPI DMA State Word 1 (TCPPIDMASTATEW1)
The Transmit CPPI DMA State Word 1 (TCPPIDMASTATEW1) is shown in Figure 47 and described in
Table 48.
Figure 47. Transmit CPPI DMA State Word 1 (TCPPIDMASTATEW1)
31
16
SOP_DESCRIPTOR_PTR
R/W-0
15
1
0
SOP_DESCRIPTOR_PTR
2
Reserved
IN_PACKET
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 48. Transmit CPPI DMA State Word 1 (TCPPIDMASTATEW1) Field Descriptions
Bit
31-2
Field
SOP_DESCRIPTOR_PTR
Value
Description
0-3FFF FFFFh Start of Packet Buffer Descriptor Pointer
30 bit pointer to 32-bit aligned descriptor which is the first descriptor for the
current packet
1
Reserved
0
IN_PACKET
100
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0
Reserved
Flag indicating the DMA is in the middle of processing a packet
0
Not currently in packet
1
Currently in packet
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4.33 Transmit CPPI DMA State Word 2 (TCPPIDMASTATEW2)
The Transmit CPPI DMA State Word 2 (TCPPIDMASTATEW2) is shown in Figure 48 and described in
Table 49.
Figure 48. Transmit CPPI DMA State Word 2 (TCPPIDMASTATEW2)
31
16
CURR_DESCRIPTOR_PTR
R/W-0
15
1
0
CURR_DESCRIPTOR_PTR
2
TRUNCATED_NON_EOP
Reserved
R/W-0
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 49. Transmit CPPI DMA State Word 2 (TCPPIDMASTATEW2) Field Descriptions
Bit
31-2
Field
Value
CURR_DESCRIPTOR_PTR
Description
0-3FFF FFFFh Current Buffer Descriptor Pointer
30 bit pointer to 32-bit aligned descriptor for buffer from which data is currently
being transmitted
1
0
TRUNCATED_NON_EOP
Reserved
Flag indicating that packet truncation has occurred on the current packet within a
buffer which was not designated as the end of packet buff
0
Truncation within non end of packet buffer has not occurred
1
Truncation within non end of packet has occurred
0
Reserved
4.34 Transmit CPPI DMA State Word 3 (TCPPIDMASTATEW3)
The Transmit CPPI DMA State Word 3 (TCPPIDMASTATEW3) is shown in Figure 49 and described in
Table 50.
Figure 49. Transmit CPPI DMA State Word 3 (TCPPIDMASTATEW3)
31
0
CURR_BUFFER_PTR
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 50. Transmit CPPI DMA State Word 3 (TCPPIDMASTATEW3) Field Descriptions
Bit
31-0
Field
CURR_BUFFER_PTR
Value
Description
0-FFFF FFFFh Current Buffer Pointer
32 bit absolute byte address in buffer from which data is currently being
transmitted
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4.35 Transmit CPPI DMA State Word 4 (TCPPIDMASTATEW4)
The Transmit CPPI DMA State Word 4 (TCPPIDMASTATEW4) is shown in Figure 50 and described in
Table 51.
Figure 50. Transmit CPPI DMA State Word 4 (TCPPIDMASTATEW4)
31
24
23
18
17
16
DESC_MSG
Reserved
CURR_BUFFER_EOP
CURR_BUFFER_SOP
R/W-0
R-0
R/W-0
R/W-0
15
0
CURR_BUFFER_LENGTH
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 51. Transmit CPPI DMA State Word 4 (TCPPIDMASTATEW4) Field Descriptions
Field
Value
Description
31-24 DESC_MSG
Bit
0-FFh
Descriptor Message
Byte which is passed from the SOP Tx Descriptor to the SOP Receive
descriptor. Used to tag packets.
23-18 Reserved
17
CURR_BUFFER_EOP
0
0-1
Reserved
Current Buffer is EOP
Flag indicating whether or not the current buffer that is being transmitted from is
the end of packet buffer
16
CURR_BUFFER_SOP
0-1
Current Buffer is SOP
Flag indicating whether or not the current buffer that is being transmitted from is
the start of packet buffer
15-0
CURR_BUFFER_LENGTH
0-FFFFh
Current Buffer Length
Indicates how many valid bytes remain in the current buffer that is being
transmitted from
102
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4.36 Transmit CPPI DMA State Word 5 (TCPPIDMASTATEW5)
The Transmit CPPI DMA State Word 5 (TCPPIDMASTATEW5) is shown in Figure 51 and described in
Table 52.
Figure 51. Transmit CPPI DMA State Word 5 (TCPPIDMASTATEW5)
31
16
REM_LENGTH
R/W-0
15
0
LENGTH
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 52. Transmit CPPI DMA State Word 5 (TCPPIDMASTATEW5) Field Descriptions
Bit
Field
Value
31-16
REM_LENGTH
0-FFFFh
15-0
LENGTH
0-FFFFh
Description
Remaining Packet Length
Indicates how many bytes remain to be transmitted in the packet before truncation occurs
Packet Length
Indicates how many bytes are contained in the packet. This value is copied from the
packet-length field in Word 3 of the SOP Descriptor. This value is written into the AAL5 trailer
for the packet.
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4.37 Transmit CPPI Completion Pointer (TCPPICOMPPTR)
The Transmit CPPI Completion Pointer (TCPPICOMPPTR) is shown in Figure 52 and described in
Table 53.
Figure 52. Transmit CPPI Completion Pointer (TCPPICOMPPTR)
31
16
DESC_ADDR
R/W-0
15
1
0
DESC_ADDR
2
Reserved
WRBK_MODE
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 53. Transmit CPPI Completion Pointer (TCPPICOMPPTR) Field Descriptions
Bit
31-2
Field
DESC_ADDR
Value
0-3FFF FFFFh
Description
Descriptor Address
This field contains the 30 bit word aligned pointer of the end of packet descriptor that the
DMA has last processed
104
1
Reserved
0
WRBK_MODE
0
Reserved
Writeback/Compare Mode. This bit controls the action that is to be taken when this location
is written.
0
Compare Mode. Indicates that the value that is presented on bits 31:2 of the write data
should be compared against the value that is currently contained in bits 31:2 of this location.
If the two match, the interrupt bit corresponding to this Tx Queue should be deasserted.
1
Writeback Mode. Indicates that the value that is presented on bits 31:2 of the write data
should be written to this location and the interrupt for this Tx Queue should be asserted. This
bit is read as zero.
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4.38 Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0)
The Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0) is shown in Figure 53 and described in
Table 54.
Figure 53. Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0)
31
16
Reserved
R-0
15
8
7
0
Reserved
SOP_BUFFER_OFFSET
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 54. Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0) Field Descriptions
Bit
Field
Value
31-8
Reserved
7-0
SOP_BUFFER_OFFSET
Description
0-7FFF FFh
0-FFh
Reserved
Start of Packet Buffer Offset
Controls how many bytes the Receive DMA will skip at the beginning of the start
of packet buffer before beginning to fill the buffer with receive data. This field is
programmed by the Host software when the channel is set up to facilitate
addition of various protocol encapsulation headers for retransmission of received
packets.
4.39 Receive CPPI DMA State Word 1 (RCPPIDMASTATEW1)
The Receive CPPI DMA State Word 1 (RCPPIDMASTATEW1) is shown in Figure 54 and described in
Table 55.
Figure 54. Receive CPPI DMA State Word 1 (RCPPIDMASTATEW1)
31
16
RXQ_HEAD_PTR
R/W-0
15
2
1
0
RXQ_HEAD_PTR
Reserved
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 55. Receive CPPI DMA State Word 1 (RCPPIDMASTATEW1) Field Descriptions
Bit
31-2
Field
RXQ_HEAD_PTR
Value
0-1FFF FFFFh
Description
Receive Queue Head Pointer
30-bit pointer to 32-bit aligned descriptor at the head of the Receive queue
1-0
Reserved
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0
Reserved
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4.40 Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2)
The Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2) is shown in Figure 55 and described in
Table 56.
Figure 55. Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2)
31
16
SOP_DESCRIPTOR_PTR
R/W-0
15
1
0
SOP_DESCRIPTOR_PTR
2
Reserved
IN_PACKET
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 56. Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2) Field Descriptions
Bit
31-2
Field
Value
SOP_DESCRIPTOR_PTR
Description
0-1FFF FFFFh Start of Packet Buffer Descriptor Pointer
30-bit pointer to 32-bit aligned descriptor which is the first descriptor for the
current packet
1
Reserved
0
IN_PACKET
0
Reserved
Flag indicating the DMA is in the middle of processing a packet 0: Not currently
in packet
0
Not currently in packet
1
Currently in packet
4.41 Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3)
The Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3) is shown in Figure 56 and described in
Table 57.
Figure 56. Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3)
31
16
CURR_DESCRIPTOR_PTR
R/W-0
15
1
0
CURR_DESCRIPTOR_PTR
Reserved
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 57. Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3) Field Descriptions
Bit
31-2
Field
CURR_DESCRIPTOR_PTR
Value
Description
0-3FFF FFFFh Current Buffer Descriptor Pointer
30-bit pointer to 32-bit aligned descriptor for buffer into which data is currently
being received
1-0
106
Reserved
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0
Reserved
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4.42 Receive CPPI DMA State Word 4 (RCPPIDMASTATEW4)
The Receive CPPI DMA State Word 4 (RCPPIDMASTATEW4) is shown in Figure 57 and described in
Table 58.
Figure 57. Receive CPPI DMA State Word 4 (RCPPIDMASTATEW4)
31
0
CURR_BUFFER_PTR
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 58. Receive CPPI DMA State Word 4 (RCPPIDMASTATEW4) Field Descriptions
Bit
31-0
Field
Value
CURR_BUFFER_PTR
Description
0-FFFF FFFFh
Current Buffer Pointer
32-bit absolute byte address in buffer into which data is currently being received
4.43 Receive CPPI DMA State Word 5 (RCPPIDMASTATEW5)
The Receive CPPI DMA State Word 5 (RCPPIDMASTATEW5) is shown in Figure 58 and described in
Table 59.
Figure 58. Receive CPPI DMA State Word 5 (RCPPIDMASTATEW5)
31
16
PKT_LENGTH
R/W-0
15
0
CURR_BUFFER_LENGTH
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 59. Receive CPPI DMA State Word 5 (RCPPIDMASTATEW5) Field Descriptions
Bit
Field
31-16 PKT_LENGTH
Value
0-FFFFh
Description
Packet Length
Indicates how many bytes are contained in the packet. This value is written into
bits 15:0 of Word 3 of the SOP Descriptor during end of packet processing.
15-0
CURR_BUFFER_LENGTH
0-FFFFh
Current Buffer Length
Indicates how many free bytes remain in the current buffer that is being received
into
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4.44 Receive CPPI DMA State Word 6 (RCPPIDMASTATEW6)
The Receive CPPI DMA State Word 6 (RCPPIDMASTATEW6) is shown in Figure 59 and described in
Table 60.
Figure 59. Receive CPPI DMA State Word 6 (RCPPIDMASTATEW6)
31
16
SOP_BUFFER_BYTECNT
R/W-0
15
0
CURR_BUFFER_BYTECNT
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 60. Receive CPPI DMA State Word 6 (RCPPIDMASTATEW6) Field Descriptions
Bit
Field
31-16 SOP_BUFFER_BYTECNT
Value
0-FFFFh
Description
Packet Length
Indicates how many bytes are contained in the packet. This value is written into
bits 15:0 of Word 3 of the SOP Descriptor during end of packet processing.
15-0
CURR_BUFFER_BYTECNT
0-FFFFh
Current Buffer Length
Indicates how many free bytes remain in the current buffer that is being received
into
108
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4.45 Receive CPPI Completion Pointer (RCPPICOMPPTR)
The Receive CPPI Completion Pointer (RCPPICOMPPTR) is shown in Figure 60 and described in
Table 61.
Figure 60. Receive CPPI Completion Pointer (RCPPICOMPPTR)
31
16
DESC_ADDR
R/W-0
15
1
0
DESC_ADDR
2
Reserved
RDBK_MODE
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 61. Receive CPPI Completion Pointer (RCPPICOMPPTR) Field Descriptions
Bit
Field
31-2
Value
DESC_ADDR
Description
0-7FFF FFFFh
Descriptor Address
This field contains the 30 bit word aligned pointer of the end of packet descriptor that the
DMA has last processed.
1
Reserved
0
RDBK_MODE
0
Reserved
Readback / Compare Mode
0
Compare Mode. Indicates that the value that is presented on bits 31:2 of the read data
should be compared against the value that is currently contained in bits 31:2 of this location.
If the two match, the interrupt bit corresponding to this Receive Queue should be deasserted.
1
Readback Mode. Indicates that the value that is presented on bits 31:2 of the read data
should be read from this location and the interrupt for this Receive Queue should be
asserted. This bit is read as zero.
4.46 Function Address Register (FADDR)
The Function Address Register (FADDR) is shown in Figure 61 and described in Table 62.
Figure 61. Function Address Register (FADDR)
7
6
0
Reserved
FUNCADDR
R-0
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 62. Function Address Register (FADDR) Field Descriptions
Bit
7
6-0
Field
Value
Reserved
FUNCADDR
0
0-7Fh
Description
Reserved
7_bit address of the peripheral part of the transaction
When used in Peripheral mode (DevCtl.D2=0), this register should be written with the address
received through a SET_ADDRESS command, which will then be used for decoding the function
address in subsequent token packets.
When used in Host mode (DevCtl.D2=1), this register should be set to the value sent in a
SET_ADDRESS command during device enumeration as the address for the peripheral device.
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4.47 Power Management Register (POWER)
The Power Management Register (POWER) is shown in Figure 62 and described in Table 63.
Figure 62. Power Management Register (POWER)
7
6
5
4
3
2
1
0
ISOUPDATE
SOFTCONN
HSEN
HSMODE
RESET
RESUME
SUSPENDM
ENSUSPM
R/W-0
R/W-0
R/W-1
R-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 63. Power Management Register (POWER) Field Descriptions
Bit
110
Field
Value
Description
7
ISOUPDATE
0-1
When set, the USB controller will wait for an SOF token from the time TxPktRdy is set before
sending the packet. If an IN token is received before an SOF token, then a zero length data packet
will be sent. Note: This is only valid in Peripheral Mode. This bit only affects endpoints performing
Isochronous transfers.
6
SOFTCONN
0-1
If Soft Connect/Disconnect feature is enabled, then the USB D+/D- lines are enabled when this bit
is set and tri-stated when this bit is cleared. Note: This is only valid in Peripheral Mode.
5
HSEN
0-1
When set, the USB controller will negotiate for high-speed mode when the device is reset by the
hub. If not set, the device will only operate in full-speed mode.
4
HSMODE
0-1
This bit is set when the USB controller has successfully negotiated for high-speed mode.
3
RESET
0-1
This bit is set when Reset signaling is present on the bus. Note: This bit is Read/Write in Host
Mode, but read-only in Peripheral Mode.
2
RESUME
0-1
Set to generate Resume signaling when the controller is in Suspend mode. The bit should be
cleared after 10 ms (a maximum of 15 ms) to end Resume signaling. In Host mode, this bit is also
automatically set when Resume signaling from the target is detected while the USB controller is
suspended.
1
SUSPENDM
0-1
In Host mode, this bit should be set to enter Suspend mode. In Peripheral mode, this bit is set on
entry into Suspend mode. It is cleared when the interrupt register is read, or the RESUME bit is set.
0
ENSUSPM
0-1
Set to enable the SUSPENDM output.
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4.48 Interrupt Register for Endpoint 0 Plus Transmit Endpoints 1 to 4 (INTRTX)
The Interrupt Register for Endpoint 0 Plus Transmit Endpoints 1 to 4 (INTRTX) is shown in Figure 63 and
described in Table 64.
Figure 63. Interrupt Register for Endpoint 0 Plus Tx Endpoints 1 to 4 (INTRTX)
15
8
Reserved
R-0
7
4
3
2
1
0
Reserved
5
EP4TX
EP3TX
EP2TX
EP1TX
EP0
R-0
R-0
R-0
R-0
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 64. Interrupt Register for Endpoint 0 Plus Transmit Endpoints 1 to 4 (INTRTX)
Field Descriptions
Bit
15-5
Field
Value
Reserved
0
Description
Reserved
4
EP4TX
0-1
Transmit Endpoint 4 interrupt active
3
EP3TX
0-1
Transmit Endpoint 3 interrupt active
2
EP2TX
0-1
Transmit Endpoint 2 interrupt active
1
EP1TX
0-1
Transmit Endpoint 1 interrupt active
0
EP0
0-1
Endpoint 0 interrupt active
4.49 Interrupt Register for Receive Endpoints 1 to 4 (INTRRX)
The Interrupt Register for Receive Endpoints 1 to 4 (INTRRX) is shown in Figure 64 and described in
Table 65.
Figure 64. Interrupt Register for Receive Endpoints 1 to 4 (INTRRX)
31
16
Reserved
R-0
15
5
4
3
2
1
0
Reserved
EP4RX
EP3RX
EP2RX
EP1RX
Reserved
R-0
R-0
R-0
R-0
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 65. Interrupt Register for Receive Endpoints 1 to 4 (INTRRX) Field Descriptions
Bit
15-5
Field
Value
Reserved
0
Description
Reserved
4
EP4RX
0-1
Receive Endpoint 4 interrupt active
3
EP3RX
0-1
Receive Endpoint 3 interrupt active
2
EP2RX
0-1
Receive Endpoint 2 interrupt active
1
EP1RX
0-1
Receive Endpoint 1 interrupt active
0
Reserved
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Reserved
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4.50 Interrupt Enable Register for INTRTX (INTRTXE)
The Interrupt Enable Register for INTRTX (INTRTXE) is shown in Figure 65 and described in Table 66.
Figure 65. Interrupt Enable Register for INTRTX (INTRTXE)
15
8
Reserved
R-0
7
4
3
2
1
0
Reserved
5
EP4TX
EP3TX
EP2TX
EP1TX
EP0
R-0
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 66. Interrupt Enable Register for INTRTX (INTRTXE) Field Descriptions
Bit
Field
15-5
Value
Reserved
0
Description
Reserved
4
EP4TX
0-1
Transmit Endpoint 4 interrupt active
3
EP3TX
0-1
Transmit Endpoint 3 interrupt active
2
EP2TX
0-1
Transmit Endpoint 2 interrupt active
1
EP1TX
0-1
Transmit Endpoint 1 interrupt active
0
EP0
0-1
Endpoint 0 interrupt active
4.51 Interrupt Enable Register for INTRRX (INTRRXE)
The Interrupt Enable Register for INTRRX (INTRRXE) is shown in Figure 66 and described in Table 67.
Figure 66. Interrupt Enable Register for INTRRX (INTRRXE)
15
8
Reserved
R-0
7
4
3
2
1
0
Reserved
5
EP4RX
EP3RX
EP2RX
EP1RX
Reserved
R-0
R/W-1
R/W-1
R/W-1
R/W-1
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 67. Interrupt Enable Register for INTRRX (INTRRXE) Field Descriptions
Bit
15-5
112
Field
Reserved
Value
0
Description
Reserved
4
EP4RX
0-1
Receive Endpoint 4 interrupt active
3
EP3RX
0-1
Receive Endpoint 3 interrupt active
2
EP2RX
0-1
Receive Endpoint 2 interrupt active
1
EP1RX
0-1
Receive Endpoint 1 interrupt active
0
Reserved
0
Reserved
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4.52 Interrupt Register for Common USB Interrupts (INTRUSB)
The Interrupt Register for Common USB Interrupts (INTRUSB) is shown in Figure 67 and described in
Table 68.
Note:
IMPORTANT: Unless the UINT bit of CTRLR is set, do not read or write this register directly.
Use the INTSRCR register instead.
Figure 67. Interrupt Register for Common USB Interrupts (INTRUSB)
7
6
5
4
3
2
1
0
VBUSERR
SESSREQ
DISCON
CONN
SOF
RESET_BABBLE
RESUME
SUSPEND
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 68. Interrupt Register for Common USB Interrupts (INTRUSB) Field Descriptions
Bit
Field
Value Description
7
VBUSERR
0-1
Set when VBus drops below the VBus valid threshold during a session. Only valid when the USB
controller is 'A' device. All active interrupts will be cleared when this register is read.
6
SESSREQ
0-1
Set when session request signaling has been detected. Only valid when USB controller is 'A' device.
5
DISCON
0-1
Set in host mode when a device disconnect is detected. Set in peripheral mode when a session
ends.
4
CONN
0-1
Set when a device connection is detected. Only valid in host mode.
3
SOF
0-1
Set when a new frame starts.
2
RESET_BABBLE
0-1
Set in peripheral mode when reset signaling is detected on the bus set in host mode when babble is
detected.
1
RESUME
0-1
Set when resume signaling is detected on the bus while the USB controller is in suspend mode.
0
SUSPEND
0-1
Set when suspend signaling is detected on the bus only valid in peripheral mode.
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4.53 Interrupt Enable Register for INTRUSB (INTRUSBE)
The Interrupt Enable Register for INTRUSB (INTRUSBE) is shown in Figure 68 and described in Table 69.
Note:
IMPORTANT: Unless the UINT bit of CTRLR is set, do not read or write this register directly.
Use the INTSETR/INTCLRR registers instead.
Figure 68. Interrupt Enable Register for INTRUSB (INTRUSBE)
7
6
5
4
3
2
1
0
VBUSERR
SESSREQ
DISCON
CONN
SOF
RESET_BABBLE
RESUME
SUSPEND
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-1
R/W-1
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 69. Interrupt Enable Register for INTRUSB (INTRUSBE) Field Descriptions
Bit
114
Field
Value
Description
7
VBUSERR
0-1
Vbus error interrupt enable
6
SESSREQ
0-1
Session request interrupt enable
5
DISCON
0-1
Disconnect interrupt enable
4
CONN
0-1
Connect interrupt enable
3
SOF
0-1
Start of frame interrupt enable
2
RESET_BABBLE
0-1
Reset interrupt enable
1
RESUME
0-1
Resume interrupt enable
0
SUSPEND
0-1
Suspend interrupt enable
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4.54 Frame Number Register (FRAME)
The Frame Number Register (FRAME) is shown in Figure 69 and described in Table 70.
Figure 69. Frame Number Register (FRAME)
15
11
10
0
Reserved
FRAMENUMBER
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 70. Frame Number Register (FRAME) Field Descriptions
Bit
Field
15-11
Reserved
10-0
FRAMENUMBER
Value
0
Description
Reserved
0-7FFh Last received frame number
4.55 Index Register for Selecting the Endpoint Status and Control Registers (INDEX)
The Index Register for Selecting the Endpoint Status and Control Registers (INDEX) is shown in Figure 70
and described in Table 71.
Figure 70. Index Register for Selecting the Endpoint Status and Control Registers (INDEX)
7
4
3
0
Reserved
EPSEL
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 71. Index Register for Selecting the Endpoint Status and Control Registers (INDEX)
Field Descriptions
Bit
Field
7-4
Reserved
3-0
EPSEL
Value
0
0-Fh
Description
Reserved
Each transmit endpoint and each receive endpoint have their own set of control/status registers.
EPSEL determines which endpoint control/status registers are accessed.
Before accessing an endpoint's control/status registers, the endpoint number should be written to
the Index register to ensure that the correct control/status registers appear in the memory map.
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4.56 Register to Enable the USB 2.0 Test Modes (TESTMODE)
The Register to Enable the USB 2.0 Test Modes (TESTMODE) is shown in Figure 71 and described in
Table 72.
Figure 71. Register to Enable the USB 2.0 Test Modes (TESTMODE)
7
6
5
4
3
2
1
0
FORCE_HOST
FIFO_ACCESS
FORCE_FS
FORCE_HS
TEST_PACKET
TEST_K
TEST_J
TEST_SE0_NAK
R/W-0
W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset
Table 72. Register to Enable the USB 2.0 Test Modes (TESTMODE) Field Descriptions
Bit
Field
Value
Description
7
FORCE_HOST
0-1
Set this bit to forcibly put the USB controller into Host mode when SESSION bit is set,
regardless of whether it is connected to any peripheral. The controller remains in Host mode
until the Session bit is cleared, even if a device is disconnected. And if the FORCE_HOST but
remains set, it will re-enter Host mode next time the SESSION bit is set. The operating speed is
determined using the FORCE_HS and FORCE_FS bits.
6
FIFO_ACCESS
0-1
Set this bit to transfer the packet in EP0 Tx FIFO to EP0 Receive FIFO. It is cleared
automatically.
5
FORCE_FS
0-1
Set this bit to force the USB controller into full-speed mode when it receives a USB reset.
4
FORCE_HS
0-1
Set this bit to force the USB controller into high-speed mode when it receives a USB reset.
3
TEST_PACKET
0-1
Set this bit to enter the Test_Packet test mode. In this mode, the USB controller repetitively
transmits a 53-byte test packet on the bus, the form of which is defined in the Universal Serial
Bus Specification Revision 2.0.
Note: The test packet has a fixed format and must be loaded into the Endpoint 0 FIFO before
the test mode is entered.
116
2
TEST_K
0-1
Set this bit to enter the Test_K test mode. In this mode, the USB controller transmits a
continuous K on the bus.
1
TEST_J
0-1
Set this bit to enter the Test_J test mode. In this mode, the USB controller transmits a
continuous J on the bus.
0
TEST_SE0_NAK
0-1
Set this bit to enter the Test_SE0_NAK test mode. In this mode, the USB controller remains in
high-speed mode, but responds to any valid IN token with a NAK.
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4.57 Maximum Packet Size for Peripheral/Host Transmit Endpoint (TXMAXP)
The Maximum Packet Size for Peripheral/Host Transmit Endpoint (TXMAXP) is shown in Figure 72 and
described in Table 73.
Figure 72. Maximum Packet Size for Peripheral/Host Transmit Endpoint (TXMAXP)
15
11
10
0
Reserved
MAXPAYLOAD
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 73. Maximum Packet Size for Peripheral/Host Transmit Endpoint (TXMAXP)
Field Descriptions
Bit
Field
15-11
Reserved
10-0
MAXPAYLOAD
Value
0
0-FFh
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Description
Reserved
The maximum payload transmitted in a single transaction. The value set can be up to 1024 bytes,
but is subject to the constraints placed by the USB Specification on packet sizes for Bulk, Interrupt,
and Isochronous transfers in full-speed and high-speed operations. The value written to this register
should match the wMaxPacketSize field of the Standard Endpoint Descriptor for the associated
endpoint. A mismatch could cause unexpected results.
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4.58 Control Status Register for Endpoint 0 in Peripheral Mode (PERI_CSR0)
The Control Status Register for Endpoint 0 in Peripheral Mode (PERI_CSR0) is shown in Figure 73 and
described in Table 74.
Figure 73. Control Status Register for Endpoint 0 in Peripheral Mode (PERI_CSR0)
15
9
8
Reserved
FLUSHFIFO
R-0
W-0
7
6
5
4
3
2
1
0
SERV_SETUPEND
SERV_RXPKTRDY
SENDSTALL
SETUPEND
DATAEND
SENTSTALL
TXPKTRDY
RXPKTRDY
W-0
W-0
W-0
R-0
W-0
R/W-0
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; W = Write only; -n = value after reset
Table 74. Control Status Register for Endpoint 0 in Peripheral Mode (PERI_CSR0)
Field Descriptions
Bit
15-9
8
Field
Reserved
FLUSHFIFO
Value Description
0
0-1
Reserved
Set this bit to flush the next packet to be transmitted/read from the Endpoint 0 FIFO. The FIFO
pointer is reset and the TXPKTRDY/RXPKTRDY bit (below) is cleared.
Note: FLUSHFIFO has no effect unless TXPKTRDY/RXPKTRDY is set.
7
SERV_SETUPEND
0-1
Set this bit to clear the SETUPEND bit. It is cleared automatically.
6
SERV_RXPKTRDY
0-1
Set this bit to clear the RXPKTRDY bit. It is cleared automatically.
5
SENDSTALL
0-1
Set this bit to terminate the current transaction. The STALL handshake will be transmitted and
then this bit will be cleared automatically.
4
SETUPEND
0-1
This bit will be set when a control transaction ends before the DATAEND bit has been set. An
interrupt will be generated, and the FIFO will be flushed at this time. The bit is cleared by the
writing a 1 to the SERV_SETUPEND bit.
3
DATAEND
0-1
Set this bit to:
1 - When setting TXPKTRDY for the last data packet
2 - When clearing RXPKTRDY after unloading the last data packet
3 - When setting TXPKTRDY for a zero length data packet. It is cleared automatically.
118
2
SENTSTALL
0-1
This bit is set when a STALL handshake is transmitted. This bit should be cleared.
1
TXPKTRDY
0-1
Set this bit after loading a data packet into the FIFO. It is cleared automatically when the data
packet has been transmitted. An interrupt is generated (if enabled) when the bit is cleared.
0
RXPKTRDY
0-1
This bit is set when a data packet has been received. An interrupt is generated when this bit is set.
This bit is cleared by setting the SERV_RXPKTRDY bit.
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4.59 Control Status Register for Endpoint 0 in Host Mode (HOST_CSR0)
The Control Status Register for Endpoint 0 in Host Mode (HOST_CSR0) is shown in Figure 74 and
described in Table 75.
Figure 74. Control Status Register for Endpoint 0 in Host Mode (HOST_CSR0)
15
11
Reserved
R-0
10
9
8
DATATOGWREN
DATATOG
FLUSHFIFO
W-0
R/W-0
W-0
7
6
5
4
3
2
1
0
NAK_TIMEOUT
STATUSPKT
REQPKT
ERROR
SETUPPKT
RXSTALL
TXPKTRDY
RXPKTRDY
W-0
R/W-0
R/W-0
W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; W = Write only; -n = value after reset
Table 75. Control Status Register for Endpoint 0 in Host Mode (HOST_CSR0) Field Descriptions
Bit
15-11
Field
Value
Reserved
0
Description
Reserved
10
DATATOGWREN
0-1
Write 1 to this bit to enable the DATATOG bit to be written. This bit is automatically cleared once
the new value is written to DATATOG.
9
DATATOG
0-1
When read, this bit indicates the current state of the EP0 data toggle. If DATATOGWREN is high,
this bit can be written with the required setting of the data toggle. If DATATOGWREN is low, any
value written to this bit is ignored.
8
FLUSHFIFO
0-1
Write 1 to this bit to flush the next packet to be transmitted/read from the Endpoint 0 FIFO. The
FIFO pointer is reset and the TXPKTRDY/RXPKTRDY bit (below) is cleared.
Note: FLUSHFIFO has no effect unless TXPKTRDY/RXPKTRDY is set.
7
NAK_TIMEOUT
0-1
This bit will be set when Endpoint 0 is halted following the receipt of NAK responses for longer than
the time set by the NAKLIMIT0 register. This bit should be cleared to allow the endpoint to
continue.
6
STATUSPKT
0-1
Set this bit at the same time as the TXPKTRDY or REQPKT bit is set, to perform a status stage
transaction. Setting this bit ensures that the data toggle is set so that a DATA1 packet is used for
the Status Stage transaction.
5
REQPKT
0-1
Set this bit to request an IN transaction. It is cleared when RXPKTRDY is set.
4
ERROR
0-1
This bit will be set when three attempts have been made to perform a transaction with no response
from the peripheral. You should clear this bit. An interrupt is generated when this bit is set.
3
SETUPPKT
0-1
Set this bit, at the same time as the TXPKTRDY bit is set, to send a SETUP token instead of an
OUT token for the transaction.
2
RXSTALL
0-1
This bit is set when a STALL handshake is received. You should clear this bit.
1
TXPKTRDY
0-1
Set this bit after loading a data packet into the FIFO. It is cleared automatically when the data
packet has been transmitted. An interrupt is generated (if enabled) when the bit is cleared.
0
RXPKTRDY
0-1
This bit is set when a data packet has been received. An interrupt is generated when this bit is set.
Clear this bit by setting the SERV_RXPKTRDY bit.
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4.60 Control Status Register for Peripheral Transmit Endpoint (PERI_TXCSR)
The Control Status Register for Peripheral Transmit Endpoint (PERI_TXCSR) is shown in Figure 75 and
described in Table 76.
Figure 75. Control Status Register for Peripheral Transmit Endpoint (PERI_TXCSR)
15
14
13
12
11
10
9
7
Reserved
ISO
MODE
DMAEN
FRCDATATOG
DMAMODE
Reserved
R-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-0
6
5
4
3
2
1
0
CLRDATATOG
SENTSTALL
SENDSTALL
FLUSHFIFO
UNDERRUN
FIFONOTEMPTY
TXPKTRDY
W-0
R/W-0
R/W-0
W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; W = Write only; -n = value after reset
Table 76. Control Status Register for Peripheral Transmit Endpoint (PERI_TXCSR)
Field Descriptions
Bit
Field
Value
15
Reserved
14
ISO
0-1
Set this bit to enable the Tx endpoint for Isochronous transfers, and clear it to enable the Tx
endpoint for Bulk or Interrupt transfers.
13
MODE
0-1
Set this bit to enable the endpoint direction as Tx, and clear the bit to enable it as Rx.
0
Description
Reserved
Note: This bit has any effect only where the same endpoint FIFO is used for both Transmit and
Receive transactions.
12
DMAEN
0-1
Set this bit to enable the DMA request for the Tx endpoint.
11
FRCDATATOG
0-1
Set this bit to force the endpoint data toggle to switch and the data packet to be cleared from the
FIFO, regardless of whether an ACK was received. This can be used by Interrupt Tx endpoints
that are used to communicate rate feedback for Isochronous endpoints.
10
DMAMODE
0-1
This bit should always be 0.
9-7
Reserved
0
Reserved
6
CLRDATATOG
0-1
Write a 1 to this bit to reset the endpoint data toggle to 0.
5
SENTSTALL
0-1
This bit is set automatically when a STALL handshake is transmitted. The FIFO is flushed and the
TXPKTRDY bit is cleared (see below). You should clear this bit.
4
SENDSTALL
0-1
Write a 1 to this bit to issue a STALL handshake to an IN token. Clear this bit to terminate the stall
condition.
3
FLUSHFIFO
0-1
Note: This bit has no effect where the endpoint is being used for Isochronous transfers.
Write a 1 to this bit to flush the next packet to be transmitted from the endpoint Tx FIFO. The FIFO
pointer is reset and the TXPKTRDY bit (below) is cleared.
Note: FlushFIFO has no effect unless TXPKTRDY is set. Also note that, if the FIFO is
double-buffered, FlushFIFO may need to be set twice to completely clear the FIFO.
120
2
UNDERRUN
0-1
This bit is set automatically if an IN token is received when TXPKTRDY is not set. You should
clear this bit.
1
FIFONOTEMPTY
0-1
This bit is set when there is at least 1 packet in the Tx FIFO. You should clear this bit.
0
TXPKTRDY
0-1
Set this bit after loading a data packet into the FIFO. It is cleared automatically when a data packet
has been transmitted. An interrupt is generated (if enabled) when the bit is cleared.
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4.61 Control Status Register for Host Transmit Endpoint (HOST_TXCSR)
The Control Status Register for Host Transmit Endpoint (HOST_TXCSR) is shown in Figure 76 and
described in Table 77.
Figure 76. Control Status Register for Host Transmit Endpoint (HOST_TXCSR)
15
14
13
12
11
10
9
8
Reserved
MODE
DMAEN
FRCDATATOG
DMAMODE
DATATOGWREN
DATATOG
R-0
R/W-0
R/W-0
R/W-0
R/W-0
W-0
R/W-0
7
6
5
4
3
2
1
0
NAK_TIMEOUT
CLRDATATOG
RXSTALL
SETUPPKT
FLUSHFIFO
ERROR
FIFONOTEMPTY
TXPKTRDY
R/W-0
W-0
R/W-0
R/W-0
W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; W = Write only; -n = value after reset
Table 77. Control Status Register for Host Transmit Endpoint (HOST_TXCSR) Field Descriptions
Bit
15-14
13
Field
Value
Reserved
MODE
0
0-1
Description
Reserved
Set this bit to enable the endpoint direction as Tx, and clear the bit to enable it as Rx.
Note: This bit has any effect only where the same endpoint FIFO is used for both Transmit and
Receive transactions.
12
DMAEN
0-1
Set this bit to enable the DMA request for the Tx endpoint.
11
FRCDATATOG
0-1
Set this bit to force the endpoint data toggle to switch and the data packet to be cleared from the
FIFO, regardless of whether an ACK was received. This can be used by Interrupt Tx endpoints that
are used to communicate rate feedback for Isochronous endpoints.
10
DMAMODE
0-1
This bit should always be 0.
9
DATATOGWREN
0-1
Write 1 to this bit to enable the DATATOG bit to be written. This bit is automatically cleared once
the new value is written to DATATOG.
8
DATATOG
0-1
When read, this bit indicates the current state of the Tx EP data toggle. If DATATOGWREN is high,
this bit can be written with the required setting of the data toggle. If DATATOGWREN is low, any
value written to this bit is ignored.
7
NAK_TIMEOUT
0-1
This bit will be set when the Tx endpoint is halted following the receipt of NAK responses for longer
than the time set as the NAKLIMIT by the TXINTERVAL register. It should be cleared to allow the
endpoint to continue.
6
CLRDATATOG
0-1
Write a 1 to this bit to reset the endpoint data toggle to 0.
5
RXSTALL
0-1
This bit is set when a STALL handshake is received. The FIFO is flushed and the TXPKTRDY bit is
cleared (see below). You should clear this bit.
4
SETUPPKT
0-1
Set this bit at the same time as TXPKTRDY is set, to send a SETUP token instead of an OUT
token for the transaction.
3
FLUSHFIFO
0-1
Note: This is valid only for Bulk endpoints.
Note: Setting this bit also clears the DATATOG bit.
Write a 1 to this bit to flush the next packet to be transmitted from the endpoint Tx FIFO. The FIFO
pointer is reset and the TXPKTRDY bit (below) is cleared.
Note: FlushFIFO has no effect unless TXPKTRDY is set. Also note that, if the FIFO is
double-buffered, FLUSHFIFO may need to be set twice to completely clear the FIFO.
2
ERROR
0-1
The USB controller sets this bit when 3 attempts have been made to send a packet and no
handshake packet has been received. You should clear this bit. An interrupt is generated when the
bit is set. This is valid only when the endpoint is operating in Bulk or Interrupt mode.
1
FIFONOTEMPTY
0-1
The USB controller sets this bit when there is at least 1 packet in the Tx FIFO.
0
TXPKTRDY
0-1
Set this bit after loading a data packet into the FIFO. It is cleared automatically when a data packet
has been transmitted. An interrupt is generated (if enabled) when the bit is cleared.
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4.62 Maximum Packet Size for Peripheral Host Receive Endpoint (RXMAXP)
The Maximum Packet Size for Peripheral Host Receive Endpoint (RXMAXP) is shown in Figure 77 and
described in Table 78.
Figure 77. Maximum Packet Size for Peripheral Host Receive Endpoint (RXMAXP)
15
11
10
0
Reserved
MAXPAYLOAD
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 78. Maximum Packet Size for Peripheral Host Receive Endpoint (RXMAXP) Field Descriptions
Bit
Field
15-11
Reserved
10-0
MAXPAYLOAD
122
Value
0
0-FFh
Description
Reserved
Defines the maximum amount of data that can be transferred through the selected Receive
endpoint in a single frame/microframe (high-speed transfers). The value set can be up to 1024
bytes, but is subject to the constraints placed by the USB Specification on packet sizes for Bulk,
Interrupt, and Isochronous transfers in full-speed and high-speed operations. The value written to
this register should match the wMaxPacketSize field of the Standard Endpoint Descriptor for the
associated endpoint. A mismatch could cause unexpected results.
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4.63 Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR)
The Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR) is shown in Figure 78 and
described in Table 79.
Figure 78. Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR)
15
14
13
12
11
8
Reserved
ISO
DMAEN
DISNYET
Reserved
R-0
R/W-0
R/W-0
R/W-0
R-0
7
6
5
4
3
2
1
0
CLRDATATOG
SENTSTALL
SENDSTALL
FLUSHFIFO
DATAERROR
OVERRUN
FIFOFULL
RXPKTRDY
W-0
R/W-0
R/W-0
W-0
R-0
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; W = Write only; -n = value after reset
Table 79. Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR)
Field Descriptions
Bit
Field
Value
15
Reserved
14
ISO
0-1
Set this bit to enable the Receive endpoint for Isochronous transfers, and clear it to enable the
Receive endpoint for Bulk/Interrupt transfers.
13
DMAEN
0-1
Set this bit to enable the DMA request for the Receive endpoints.
12
DISNYET
0-1
Set this bit to disable the sending of NYET handshakes. When set, all successfully received
Receive packets are ACKed, including at the point at which the FIFO becomes full.
0
Description
Reserved
Note: This bit only has any effect in high-speed mode, in which mode it should be set for all
Interrupt endpoints.
11-8
Reserved
0
Reserved
7
CLRDATATOG
0-1
Write a 1 to this bit to reset the endpoint data toggle to 0.
6
SENTSTALL
0-1
This bit is set when a STALL handshake is transmitted. The FIFO is flushed and the TXPKTRDY bit
is cleared (see below). You should clear this bit.
5
SENDSTALL
0-1
Write a 1 to this bit to issue a STALL handshake. Clear this bit to terminate the stall condition.
Note: This bit has no effect where the endpoint is being used for Isochronous transfers.
4
FLUSHFIFO
0-1
Write a 1 to this bit to flush the next packet to be read from the endpoint Receive FIFO. The FIFO
pointer is reset and the RXPKTRDY bit (below) is cleared.
Note: FLUSHFIFO has no effect unless RXPKTRDY is set. Also note that, if the FIFO is
double-buffered, FLUSHFIFO may need to be set twice to completely clear the FIFO.
3
DATAERROR
0-1
This bit is set when RXPKTRDY is set if the data packet has a CRC or bit-stuff error. It is cleared
when RXPKTRDY is cleared.
Note: This bit is only valid when the endpoint is operating in ISO mode. In Bulk mode, it always
returns zero.
2
OVERRUN
0-1
This bit is set if an OUT packet cannot be loaded into the Receive FIFO. You should clear this bit.
Note: This bit is only valid when the endpoint is operating in ISO mode. In Bulk mode, it always
returns zero.
1
FIFOFULL
0-1
This bit is set when no more packets can be loaded into the Receive FIFO.
0
RXPKTRDY
0-1
This bit is set when a data packet has been received. You should clear this bit when the packet has
been unloaded from the Receive FIFO. An interrupt is generated when the bit is set.
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4.64 Control Status Register for Host Receive Endpoint (HOST_RXCSR)
The Control Status Register for Host Receive Endpoint (HOST_RXCSR) is shown in Figure 79 and
described in Table 80.
Figure 79. Control Status Register for Host Receive Endpoint (HOST_RXCSR)
15
14
13
12
11
10
9
8
Reserved
DMAEN
DISNYET
Reserved
DATATOGWREN
DATATOG
Reserved
R-0
R/W-0
R/W-0
R/W-0
W-0
R/W-0
R-0
7
6
5
4
3
2
1
0
CLRDATATOG
RXSTALL
REQPKT
FLUSHFIFO
DATAERR_NAK
TIMEOUT
ERROR
FIFOFULL
RXPKTRDY
W-0
R/W-0
R/W-0
W-0
R-0
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; W = Write only; -n = value after reset
Table 80. Control Status Register for Host Receive Endpoint (HOST_RXCSR) Field Descriptions
Bit
Field
15-14 Reserved
Value Description
0
Reserved
13
DMAEN
0-1
Set this bit to enable the DMA request for the Receive endpoints.
12
DISNYET
0-1
Set this bit to disable the sending of NYET handshakes. When set, all successfully received
Receive packets are ACKED including at the point at which the FIFO becomes full.
Note: This bit only has any effect in high-speed mode, in which mode it should be set for all
Interrupt endpoints.
11
Reserved
10
DATATOGWREN
0-1
0
Write 1 to this bit to enable the DATATOG bit to be written. This bit is automatically cleared
once the new value is written to DATATOG.
9
DATATOG
0-1
When read, this bit indicates the current state of the Receive EP data toggle. If
DATATOGWREN is high, this bit can be written with the required setting of the data toggle.
If DATATOGWREN is low, any value written to this bit is ignored.
8
Reserved
7
CLRDATATOG
0-1
Write a 1 to this bit to reset the endpoint data toggle to 0.
6
RXSTALL
0-1
When a STALL handshake is received, this bit is set and an interrupt is generated. You
should clear this bit.
5
REQPKT
0-1
Write a 1 to this bit to request an IN transaction. It is cleared when RXPKTRDY is set.
4
FLUSHFIFO
0-1
Write a 1 to this bit to flush the next packet to be read from the endpoint Receive FIFO. The
FIFO pointer is reset and the RXPKTRDY bit (below) is cleared.
0
Reserved
Reserved
Note: FLUSHFIFO has no effect unless RXPKTRDY is set. Also note that, if the FIFO is
double-buffered, FLUSHFIFO may need to be set twice to completely clear the FIFO.
3
DATAERR_NAKTIMEOUT
0-1
When operating in ISO mode, this bit is set when RXPKTRDY is set if the data packet has
a CRC or bit-stuff error and cleared when RXPKTRDY is cleared. In Bulk mode, this bit will
be set when the Receive endpoint is halted following the receipt of NAK responses for
longer than the time set as the NAK Limit by the RXINTERVAL register. You should clear
this bit to allow the endpoint to continue.
2
ERROR
0-1
The USB controller sets this bit when 3 attempts have been made to receive a packet and
no data packet has been received. You should clear this bit. An interrupt is generated when
the bit is set.
Note: This bit is only valid when the transmit endpoint is operating in Bulk or Interrupt
mode. In ISO mode, it always returns zero.
1
FIFOFULL
0-1
This bit is set when no more packets can be loaded into the Receive FIFO.
0
RXPKTRDY
0-1
This bit is set when a data packet has been received. You should clear this bit when the
packet has been unloaded from the Receive FIFO. An interrupt is generated when the bit is
set.
124
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4.65 Count 0 Register (COUNT0)
The Count 0 Register (COUNT0) is shown in Figure 80 and described in Table 81.
Figure 80. Count 0 Register (COUNT0)
15
7
6
0
Reserved
EP0RXCOUNT
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 81. Count 0 Register (COUNT0) Field Descriptions
Bit
Field
Value
15-7
Reserved
6-0
EP0RXCOUNT
0
Description
Reserved
0-7Fh
Indicates the number of received data bytes in the Endpoint 0 FIFO. The value returned changes as
the contents of the FIFO change and is only valid while RXPKTRDY of PERI_CSR0 or
HOST_CSR0 is set.
4.66 Receive Count Register (RXCOUNT)
The Receive Count Register (RXCOUNT) is shown in Figure 81 and described in Table 82.
Figure 81. Receive Count Register (RXCOUNT)
15
13
12
0
Reserved
EPRXCOUNT
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 82. Receive Count Register (RXCOUNT) Field Descriptions
Bit
Field
15-13
Reserved
12-0
EPRXCOUNT
Value
0
0-1FFFh
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Description
Reserved
Holds the number of received data bytes in the packet in the Receive FIFO. The value
returned changes as the contents of the FIFO change and is only valid while RXPKTRDY of
PERI_RXCSR or HOST_RXCSR is set.
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4.67 Type Register (Host mode only) (HOST_TYPE0)
The Type Register (Host mode only) (HOST_TYPE0) is shown in Figure 82 and described in Table 83.
Figure 82. Type Register (Host mode only) (HOST_TYPE0)
7
6
5
0
SPEED
Reserved
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 83. Type Register (Host mode only) (HOST_TYPE0) Field Descriptions
Bit
Field
7-6
SPEED
5-0
Value
0-3h
Reserved
Description
Operating Speed of Target Device
0
Illegal
1
High
2h
Full
3h
Low
0
Reserved
4.68 Transmit Type Register (Host mode only) (HOST_TXTYPE)
The Transmit Type Register (Host mode only) (HOST_TXTYPE) is shown in Figure 83 and described in
Table 84.
Figure 83. Transmit Type Register (Host mode only) (HOST_TXTYPE)
7
6
5
4
3
0
SPEED
PROT
TENDPN
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 84. Transmit Type Register (Host mode only) (HOST_TXTYPE) Field Descriptions
Bit
Field
7-6
SPEED
5-4
3-0
126
PROT
TENDPN
Value
0-3h
Description
Operating Speed of Target Device
0
Illegal
1
High
2h
Full
3h
Low
0-3h
Set this to select the required protocol for the transmit endpoint
0
Control
1
Isochronous
2h
Bulk
3h
Interrupt
0-Fh
Set this value to the endpoint number contained in the transmit endpoint descriptor returned to the
USB controller during device enumeration.
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4.69 NAKLimit0 Register (Host mode only) (HOST_NAKLIMIT0)
The NAKLimit0 Register (Host mode only) (HOST_NAKLIMIT0) is shown in Figure 84 and described in
Table 85.
Figure 84. NAKLimit0 Register (Host mode only) (HOST_NAKLIMIT0)
7
5
4
0
Reserved
EP0NAKLIMIT
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 85. NAKLimit0 Register (Host mode only) (HOST_NAKLIMIT0) Field Descriptions
Bit
Field
Value
7-5
Reserved
4-0
EP0NAKLIMIT
0
0-1Fh
Description
Reserved
Sets the number of frames/microframes (high-speed transfers) after which Endpoint 0 should time
out on receiving a stream of NAK responses. The number of frames/microframes selected is 2(—1)
(where m is the value set in the register, valid values 2-16). If the host receives NAK responses
from the target for more frames than the number represented by the Limit set in this register, the
endpoint will be halted.
Note: A value of 0 or 1 disables the NAK timeout function.
4.70 Transmit Interval Register (Host mode only) (HOST_TXINTERVAL)
The Transmit Interval Register (Host mode only) (HOST_TXINTERVAL) is shown in Figure 85 and
described in Table 86.
Figure 85. Transmit Interval Register (Host mode only) (HOST_TXINTERVAL)
7
0
POLINTVL_NAKLIMIT
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 86. Transmit Interval Register (Host mode only) (HOST_TXINTERVAL) Field Descriptions
Bit
Field
Value
Description
7-0
POLINTVL_NAKLIMIT
0-FFh
For Interrupt and Isochronous transfers, defines the polling interval for the
currently-selected transmit endpoint. For Bulk endpoints, this register sets the number of
frames/microframes after which the endpoint should timeout on receiving a stream of NAK
responses There is a transmit Interval register for each configured transmit endpoint
(except Endpoint 0). In each case the value that is set defines a number of
frames/microframes (High Speed transfers), as follows:
Transfer Type Speed Valid values (m) Interpretation
Interrupt Low Speed or Full Speed 1 - 255 Polling interval is m frames
High Speed 1 - 16 Polling interval is 2(—1) microframes
Isochronous Full Speed or High Speed 1 - 16 Polling interval is 2(—1) frames/microframes
Bulk Full Speed or High Speed 2 - 16 NAK Limit is 2(—1) frames/microframes
Note: A value of 0 or 1 disables the NAK timeout function.
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4.71 Receive Type Register (Host mode only) (HOST_RXTYPE)
The Receive Type Register (Host mode only) (HOST_RXTYPE) is shown in Figure 86 and described in
Table 87.
Figure 86. Receive Type Register (Host mode only) (HOST_RXTYPE)
7
6
5
4
3
0
SPEED
PROT
RENDPN
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 87. Receive Type Register (Host mode only) (HOST_RXTYPE) Field Descriptions
Bit
Field
7-6
SPEED
5-4
3-0
128
PROT
RENDPN
Value
0-3h
Description
Operating Speed of Target Device
0
Illegal
1
High
2h
Full
3h
Low
0-3h
Set this to select the required protocol for the transmit endpoint
0
Control
1
Isochronous
2h
Bulk
3h
Interrupt
0-Fh
Set this value to the endpoint number contained in the Receive endpoint descriptor returned to the
USB controller during device enumeration
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4.72 Receive Interval Register (Host mode only) (HOST_RXINTERVAL)
The Receive Interval Register (Host mode only) (HOST_RXINTERVAL) is shown in Figure 87 and
described in Table 88.
Figure 87. Receive Interval Register (Host mode only) (HOST_RXINTERVAL)
7
0
POLINTVL_NAKLIMIT
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 88. Receive Interval Register (Host mode only) (HOST_RXINTERVAL) Field Descriptions
Bit
Field
Value
Description
7-0
POLINTVL_NAKLIMIT
0-FFh
For Interrupt and Isochronous transfers, defines the polling interval for the
currently-selected transmit endpoint For Bulk endpoints, this register sets the number of
frames/microframes after which the endpoint should timeout on receiving a stream of NAK
responses. There is a transmit Interval register for each configured transmit endpoint
(except Endpoint 0). In each case the value that is set defines a number of
frames/microframes (High Speed transfers), as follows:
Transfer Type Speed Valid values (m) Interpretation
Interrupt Low Speed or Full Speed 1 - 255 Polling interval is m frames
High Speed 1 - 16 Polling interval is 2(—1) microframes
Isochronous Full Speed or High Speed 1 - 16 Polling interval is 2(—1) frames/microframes
Bulk Full Speed or High Speed 2 - 16 NAK Limit is 2(—1) frames/microframes
Note: A value of 0 or 1 disables the NAK timeout function
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4.73 Configuration Data Register (CONFIGDATA)
The configuration data register (CONFIGDATA) is shown in Figure 88 and described in Table 89.
Figure 88. Configuration Data Register (CONFIGDATA)
7
6
5
4
3
2
1
0
MPRXE
MPTXE
BIGENDIAN
HBRXE
HBTXE
DYNFIFO
SOFTCONE
UTMIDATAWIDTH
R-0
R-0
R-0
R-0
R-0
R-1
R-1
R-0
LEGEND: R = Read only; -n = value after reset
Table 89. Configuration Data Register (CONFIGDATA) Field Descriptions
Bit
7
6
5
4
3
2
1
0
130
Field
Value
MPRXE
Description
Indicates automatic amalgamation of bulk packets.
0
Automatic amalgamation of bulk packets is not selected.
1
Automatic amalgamation of bulk packets is selected.
MPTXE
Indicates automatic splitting of bulk packets.
0
Automatic splitting of bulk packets is not selected.
1
Automatic splitting of bulk packets is selected.
BIGENDIAN
Indicates endian ordering.
0
Little-endian ordering is selected.
1
Big-endian ordering is selected.
HBRXE
Indicates high-bandwidth Rx ISO endpoint support.
0
High-bandwidth Rx ISO endpoint support is not selected.
1
High-bandwidth Rx ISO endpoint support is selected.
HBTXE
Indicates high-bandwidth Tx ISO endpoint support.
0
High-bandwidth Tx ISO endpoint support is not selected.
1
High-bandwidth Tx ISO endpoint support is selected.
DYNFIFO
Indicates dynamic FIFO sizing.
0
Dynamic FIFO sizing option is not selected.
1
Dynamic FIFO sizing option is selected.
SOFTCONE
Indicates soft connect/disconnect.
0
Soft connect/disconnect option is not selected
1
Soft connect/disconnect option is selected
UTMIDATAWIDTH
Indicates selected UTMI data width.
0
8 bits
1
16 bits
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4.74 Transmit and Receive FIFO Register for Endpoint 0 (FIFO0)
The Transmit and Receive FIFO Register for Endpoint 0 (FIFO0) is shown in Figure 89 and described in
Table 90.
Figure 89. Transmit and Receive FIFO Register for Endpoint 0 (FIFO0)
31
0
DATA
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 90. Transmit and Receive FIFO Register for Endpoint 0 (FIFO0) Field Descriptions
Bit
Field
Value
31-0
DATA
0-FFFF FFFFh
Description
Writing to these addresses loads data into the Transmit FIFO for the corresponding endpoint.
Reading from these addresses unloads data from the Receive FIFO for the corresponding
endpoint.
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4.75 Transmit and Receive FIFO Register for Endpoint 1 (FIFO1)
The Transmit and Receive FIFO Register for Endpoint 1 (FIFO1) is shown in Figure 90 and described in
Table 91.
Figure 90. Transmit and Receive FIFO Register for Endpoint 1 (FIFO1)
31
0
DATA
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 91. Transmit and Receive FIFO Register for Endpoint 1 (FIFO1) Field Descriptions
Bit
Field
Value
31-0
DATA
0-FFFF FFFF
Description
Writing to these addresses loads data into the Transmit FIFO for the corresponding endpoint.
Reading from these addresses unloads data from the Receive FIFO for the corresponding
endpoint.
4.76 Transmit and Receive FIFO Register for Endpoint 2 (FIFO2)
The Transmit and Receive FIFO Register for Endpoint 2 (FIFO2) is shown in Figure 91 and described in
Table 92.
Figure 91. Transmit and Receive FIFO Register for Endpoint 2 (FIFO2)
31
0
DATA
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 92. Transmit and Receive FIFO Register for Endpoint 2 (FIFO2) Field Descriptions
Bit
Field
Value
31-0
DATA
0-FFFF FFFFh
Description
Writing to these addresses loads data into the Transmit FIFO for the corresponding endpoint.
Reading from these addresses unloads data from the Receive FIFO for the corresponding
endpoint.
132
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4.77 Transmit and Receive FIFO Register for Endpoint 3 (FIFO3)
The Transmit and Receive FIFO Register for Endpoint 3 (FIFO3) is shown in Figure 92 and described in
Table 93.
Figure 92. Transmit and Receive FIFO Register for Endpoint 3 (FIFO3)
31
0
DATA
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 93. Transmit and Receive FIFO Register for Endpoint 3 (FIFO3) Field Descriptions
Bit
Field
Value
31-0
DATA
0-FFFF FFFFh
Description
Writing to these addresses loads data into the Transmit FIFO for the corresponding endpoint.
Reading from these addresses unloads data from the Receive FIFO for the corresponding
endpoint.
4.78 Transmit and Receive FIFO Register for Endpoint 4 (FIFO4)
The Transmit and Receive FIFO Register for Endpoint 4 (FIFO4) is shown in Figure 93 and described in
Table 94.
Figure 93. Transmit and Receive FIFO Register for Endpoint 4 (FIFO4)
31
0
DATA
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 94. Transmit and Receive FIFO Register for Endpoint 4 (FIFO4) Field Descriptions
Bit
Field
Value
31-0
DATA
0-FFFF FFFFh
Description
Writing to these addresses loads data into the Transmit FIFO for the corresponding endpoint.
Reading from these addresses unloads data from the Receive FIFO for the corresponding
endpoint.
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4.79 OTG Device Control Register (DEVCTL)
The OTG Device Control Register (DEVCTL) is shown in Figure 94 and described in Table 95.
Figure 94. OTG Device Control Register (DEVCTL)
7
6
5
2
1
0
BDEVICE
FSDEV
LSDEV
4
VBUS
3
HOSTMODE
HOSTREQ
SESSION
R-0
R-0
R-0
R-0
R-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 95. OTG Device Control Register (DEVCTL) Field Descriptions
Bit
7
Field
Value
BDEVICE
Description
This read-only bit indicates whether the USB controller is operating as the 'A' device or the 'B'
device.
0
'A' device
1
'B' device
Only valid while a session is in progress.
6
FSDEV
0-1
This read-only bit is set when a full-speed or high-speed device has been detected being connected
to the port (high-speed devices are distinguished from full-speed by checking for high-speed chirps
when the device is reset). Only valid in Host mode.
5
LSDEV
0-1
This read-only bit is set when a low-speed device has been detected being connected to the port.
Only valid in Host mode.
4-3
VBUS
0-3h
These read-only bits encode the current VBus level as follows:
134
0
Below Session End
1
Above Session End, below AValid
2h
Above AValid, below VBusValid
3h
Above VBusValid
2
HOSTMODE
0-1
This read-only bit is set when the USB controller is acting as a Host.
1
HOSTREQ
0-1
When set, the USB controller will initiate the Host Negotiation when Suspend mode is entered. It is
cleared when Host Negotiation is completed. ('B' device only)
0
SESSION
0-1
When operating as an 'A' device, you must set or clear this bit start or end a session. When
operating as a 'B' device, this bit is set/cleared by the USB controller when a session starts/ends.
You must also set this bit to initiate the Session Request Protocol. When the USB controller is in
Suspend mode, you may clear the bit to perform a software disconnect.
A special software routine is required to perform SRP. Details will be made available in a later
document version.
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4.80 Transmit Endpoint FIFO Size (TXFIFOSZ)
Section 2.7 describes dynamically setting endpoint FIFO sizes.
The Transmit Endpoint FIFO Size (TXFIFOSZ) is shown in Figure 95 and described in Table 96.
Figure 95. Transmit Endpoint FIFO Size (TXFIFOSZ)
7
5
4
3
0
Reserved
DPB
SZ
R-0
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 96. Transmit Endpoint FIFO Size (TXFIFOSZ) Field Descriptions
Bit
Field
7-5
Reserved
4
Value
0
DPB
3-0
Description
Reserved
Double packet buffering enable
SZ
0
Single packet buffering is supported
1
Double packet buffering is enabled
0-Fh
Maximum packet size to be allowed (before any splitting within the FIFO of Bulk packets prior to
transmission). If m = SZ[3:0], the FIFO size is calculated as 2(m+3) for single packet buffering and
2(m+4) for dual packet buffering.
4.81 Receive Endpoint FIFO Size (RXFIFOSZ)
Section 2.7 describes dynamically setting endpoint FIFO sizes.
The Receive Endpoint FIFO Size (RXFIFOSZ) is shown in Figure 96 and described in Table 97.
Figure 96. Receive Endpoint FIFO Size (RXFIFOSZ)
7
5
4
3
0
Reserved
DPB
SZ
R-0
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 97. Receive Endpoint FIFO Size (RXFIFOSZ) Field Descriptions
Bit
Field
7-5
Reserved
4
3-0
Value
0
DPB
SZ
Description
Reserved
Double packet buffering enable
0
Single packet buffering is supported
1
Double packet buffering is enabled
0-Fh
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Maximum packet size to be allowed (before any splitting within the FIFO of Bulk packets prior to
transmission). If m = SZ[3:0], the FIFO size is calculated as 2(m+3) for single packet buffering and
2(m+4) for dual packet buffering.
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4.82 Transmit Endpoint FIFO Address (TXFIFOADDR)
Section 2.7 describes dynamically setting endpoint FIFO sizes.
The Transmit Endpoint FIFO Address (TXFIFOADDR) is shown in Figure 97 and described in Table 98.
Figure 97. Transmit Endpoint FIFO Address (TXFIFOADDR)
15
13
12
0
Reserved
ADDR
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 98. Transmit Endpoint FIFO Address (TXFIFOADDR) Field Descriptions
Bit
Field
15-13
Reserved
12-0
ADDR
Value
Description
0
Reserved
0-1FFFh
Start Address of endpoint FIFO in units of 8 bytes
If m = ADDR[12:0] then the start address is 8*m
4.83 Receive Endpoint FIFO Address (RXFIFOADDR)
Section 2.7 describes dynamically setting endpoint FIFO sizes.
The Receive Endpoint FIFO Address (RXFIFOADDR) is shown in Figure 98 and described in Table 99.
Figure 98. Receive Endpoint FIFO Address (RXFIFOADDR)
15
13
12
0
Reserved
ADDR
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 99. Receive Endpoint FIFO Address (RXFIFOADDR) Field Descriptions
Bit
Field
15-13
Reserved
12-0
ADDR
Value
0
0-1FFFh
Description
Reserved
Start Address of endpoint FIFO in units of 8 bytes
If m = ADDR[12:0], then the start address is 8*m
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4.84 Transmit Function Address (TXFUNCADDR)
The Transmit Function Address (TXFUNCADDR) is shown in Figure 99 and described in Table 100.
Figure 99. Transmit Function Address (TXFUNCADDR)
7
6
0
Reserved
FUNCADDR
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 100. Transmit Function Address (TXFUNCADDR) Field Descriptions
Bit
Field
7
Value
Reserved
6-0
0
FUNCADDR
0-7Fh
Description
Reserved
Address of target function
4.85 Transmit Hub Address (TXHUBADDR)
The Transmit Hub Address (TXHUBADDR) is shown in Figure 100 and described in Table 101.
Figure 100. Transmit Hub Address (TXHUBADDR)
7
6
0
MULT_TRANS
HUBADDR
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 101. Transmit Hub Address (TXHUBADDR) Field Descriptions
Bit
Field
7
Value
MULT_TRANS
6-0
0-1
HUBADDR
0-7Fh
Description
Set to 1 if hub has multiple transaction translators. Set to 0 if only single transaction translator is
available.
Address of hub
4.86 Transmit Hub Port (TXHUBPORT)
The Transmit Hub Port (TXHUBPORT) is shown in Figure 101 and described in Table 102.
Figure 101. Transmit Hub Port (TXHUBPORT)
7
6
0
Reserved
HUBPORT
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 102. Transmit Hub Port (TXHUBPORT) Field Descriptions
Bit
7
6-0
Field
Value
Reserved
HUBPORT
0
0-7Fh
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Description
Reserved
Port number of the hub
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4.87 Receive Function Address (RXFUNCADDR)
The Receive Function Address (RXFUNCADDR) is shown in Figure 102 and described in Table 103.
Figure 102. Receive Function Address (RXFUNCADDR)
7
6
0
Reserved
FUNCADDR
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 103. Receive Function Address (RXFUNCADDR) Field Descriptions
Bit
Field
7
Value
Reserved
6-0
0
FUNCADDR
0-7Fh
Description
Reserved
Address of target function
4.88 Receive Hub Address (RXHUBADDR)
The Receive Hub Address (RXHUBADDR) is shown in Figure 103 and described in Table 104.
Figure 103. Receive Hub Address (RXHUBADDR)
7
6
0
MULT_TRANS
HUBADDR
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 104. Receive Hub Address (RXHUBADDR) Field Descriptions
Bit
Field
7
Value
MULT_TRANS
6-0
0-1
HUBADDR
0-7Fh
Description
Set to 1 if hub has multiple transaction translators. Set to 0 if only single transaction translator is
available.
Address of hub
4.89 Receive Hub Port (RXHUBPORT)
The Receive Hub Port (RXHUBPORT) is shown in Figure 104 and described in Table 105.
Figure 104. Receive Hub Port (RXHUBPORT)
7
6
0
Reserved
HUBPORT
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 105. Receive Hub Port (RXHUBPORT) Field Descriptions
Bit
7
6-0
138
Field
Reserved
HUBPORT
Value
0
0-7Fh
Description
Reserved
Port number of hub
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Following are URLs where you can obtain information on other Texas Instruments products and application solutions:
Products
Amplifiers
Data Converters
DSP
Clocks and Timers
Interface
Logic
Power Mgmt
Microcontrollers
RFID
RF/IF and ZigBee® Solutions
amplifier.ti.com
dataconverter.ti.com
dsp.ti.com
www.ti.com/clocks
interface.ti.com
logic.ti.com
power.ti.com
microcontroller.ti.com
www.ti-rfid.com
www.ti.com/lprf
Applications
Audio
Automotive
Broadband
Digital Control
Medical
Military
Optical Networking
Security
Telephony
Video & Imaging
Wireless
www.ti.com/audio
www.ti.com/automotive
www.ti.com/broadband
www.ti.com/digitalcontrol
www.ti.com/medical
www.ti.com/military
www.ti.com/opticalnetwork
www.ti.com/security
www.ti.com/telephony
www.ti.com/video
www.ti.com/wireless
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