3. Xplained Pro
Xplained Pro is an evaluation platform that provides the full Atmel microcontroller experience. The platform consists of a series of Microcontroller (MCU) boards and extension boards that are integrated with Atmel Studio, have Atmel Software Framework (ASF) drivers and demo code, support data streaming and more. Xplained Pro MCU boards support a wide range of Xplained Pro extension boards that are connected through a set of standardized headers and connectors. Each extension board has an identification (ID) chip to uniquely identify which boards are mounted on a Xplained Pro MCU board. This information is used to present relevant user guides, application notes, datasheets and example code through Atmel Studio. Available Xplained Pro MCU and extension boards can be purchased in the Atmel
Web Store .
3.1. Embedded Debugger
The SAMDA1 Xplained Pro contains the Atmel Embedded Debugger (EDBG) for on-board debugging.
The EDBG is a composite USB device of three interfaces; a debugger, Virtual COM Port and Data
Gateway Interface (DGI).
In conjunction with Atmel Studio, the EDBG debugger interface can program and debug the
SAMDA1J16A. On the SAMDA1 Xplained Pro, the SWD interface is connected between the EDBG and the SAMDA1J16A. The Virtual COM Port is connected to a UART port on the SAMDA1J16A (see section
Embedded Debugger Implementation on page 17 for pinout), and provides an easy way to
communicate with the target application through simple terminal software. It offers variable baud rate, parity and stop bit settings. Note that the settings on the target device UART must match the settings given in the terminal software.
The DGI consists of several physical data interfaces for communication with the host computer. See
section Embedded Debugger Implementation on page 17 for available interfaces and pinout.
Communication over the interfaces is bidirectional. It can be used to send events and values from the
SAMDA1J16A as a generic printf-style data channel. Traffic over the interfaces can be timestamped on the EDBG for more accurate tracing of events. Note that timestamping imposes an overhead that reduces maximal throughput. The DGI uses a proprietary protocol, and is thus only compatible with Atmel Studio.
The EDBG controls two LEDs on SAMDA1 Xplained Pro, a power LED and a status LED.
Table 3-1
shows how the LEDs are controlled in different operation modes.
Table 3-1 EDBG LED Control
Operation mode
Normal operation
Power LED
Power LED is lit when power is applied to the board
Status LED
Activity indicator, LED flashed every time something happens on the
EDBG
The power LED and the status LED blink simultaneously Bootloader mode (idle)
Bootloader mode (firmware upgrade)
The power LED and the status LED blink in an alternating pattern
For further documentation on the EDBG, see the EDBG User Guide .
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3.2. Hardware Identification System
All Xplained Pro compatible extension boards have an Atmel ATSHA204 CryptoAuthentication
™
chip mounted. This chip contains information that identifies the extension with its name and some extra data.
When an Xplained Pro extension board is connected to an Xplained Pro MCU board the information is read and sent to Atmel Studio. The Atmel Kits extension, installed with Atmel Studio, will give relevant
information, code examples and links to the relevant documents. Table 3-2
shows the data fields stored in the ID chip with example content.
Table 3-2 Xplained Pro ID Chip Content
Data Field
Manufacturer
Product Name
Product Revision
Product Serial Number
Min. Voltage [mV]
Max. Voltage [mV]
Max. Current [mA]
Data Type
ASCII string
ASCII string
ASCII string
ASCII string uint16_t uint16_t uint16_t
Example Content
Atmel’\0’
Segment LCD1 Xplained Pro’\0’
02’\0’
1774020200000010’\0’
3000
3600
30
3.3. Power Supply
3.3.1. Power Source Selection
The SAMDA1 Xplained Pro kit can be powered by: (1) USB, (2) an external power 5V or 3.3 VCC source through the 4-pin power header, marked PWR or by (3) a LIN 12VDC input connected to HV header
VS_LIN pin. The 4-pin connector is described in section Xplained Pro Power Header
on page 10.
The available power sources and specifications are listed in
Table 3-3 .
Table 3-3 Power Sources for SAMDA1 Xplained Pro
Option
Option1
Power input Voltage Req.
Current Req.
Connector
Marking
PWR
Option 2A
External Power 1
(PWR 4-pin connector)
5V ±2 %
(±100mV) for
USB host operation.
4.3V to 5.5V if
USB host operation is not required
Embedded debugger USB
4.4V to 5.25V
(according to
USB spec)
Recommended minimum is 1A to be able to provide enough current for connected USB devices and the board itself.
Recommended maximum is 2A due to the input protection maximum current specification.
500mA (according to USB spec)
DEBUG USB
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Option
Option 2B
Option 3
Power input
Target USB
External Power 2
(HV 20-pin connector)
Voltage Req.
Current Req.
Connector
Marking
TARGET USB 4.4V to 5.25V
(according to
USB spec)
8-16VDC VREG
(HV) regulator drops it to 5VDC and then VREG
(5V) drops it to
3.3VDC to power
EDBG and
SAMDA1A device.
500mA (according to USB spec)
800mA max 12VDC power source
HV
The kit will automatically detect which power sources are available and make a selection automatically based on the following criteria:
1.
Option1: External power 5V is connected and detected. On board descrete high current output
VREG is used to regulate Vsupply from 5V to 3.3V and distribute it on the PCB and to the extension modules/PCBs. It overrides USB power source.
2.
USB power:
– Option 2A: Embedded debugger USB plug is connected or/and
– Option 2B: Target USB plug is connected
3.
Option3: External 12VDC is connected to VS_LIN pin on HV header. It can override any other source of power supplied (5V or 3V provided on PWR 4-pin header or any USB connector). Use header MCU_VCC_SEL and EXT_VCC_SEL to select source of VCC from either (1) VS_LIN or (2)
USB/PWR 4-pin header.
Note: External power is required when the 500mA through the USB connector is not enough to power a connected USB device in a USB host application.
Table 3-4
shows how MCU_VCC_SEL (MCU VCC Selection) and EXT_VCC_SEL (Extension VCC
Selection) power headers can be used to select VCC source for SAMDA1J16A and EDBG MCUs.
To select VS_LIN (12VDC) as the source of power for SAMDA1 Xplained Pro PCB connect pin1-2 on
MCU_VCC_SEL header using a jumper.
To select 5V from either of the USB connectors or select VCC_P5V or VCC_P3V3 from the 4-pin power header as the source of power for SAMDA1 Xplained Pro PCB connect pin 2-3 on EXT_VCC_SEL header using a jumper.
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Table 3-4 Selecting VCC source (VS_LIN versus USB/EXT5V/EXT3.3V)
Power Header Jumper Placement
MCU_VCC_SEL Pin 1-2
(VCC_LINTRX_P3V3 – to
- VCC)
Configuration
VCC(SAMDA1J16A)=
VCC_LINTRX_P3V3
VCC(EDBG)=
VCC_LINTRX_P3V3
Pin 2-3
(VCC_P3V3 – to - VCC)
VCC(SAMDA1J16A)=
VCC_P3V3
VCC(EDBG)= VCC_P3V3
EXT_VCC_SEL Pin 1-2
(VCC_LINTRX_P3V3 – to
- VCC)
Pin 2-3
(VCC_P3V3 – to - VCC)
VCC(EXT1/EXT2/EXT3)=
VCC_LINTRX_P3V3
VCC(EXT1/EXT2/EXT3)=
VCC_P3V3
VCC Source
VS_LIN
USB/ VCC_P5/
VCC_P3V3
VS_LIN
USB/ VCC_P5/
VCC_P3V3
3.3.2. Measuring SAM DA1 Power Consumption
As part of an evaluation of the SAMDA1 it can be of interest to measure its power consumption. Because the PCB has a separate power plane (VCC_MCU_P3V3) it is possible to measure the current consumption by measuring the current that is flowing into this plane. The VCC_MCU_P3V3 plane is connected via a jumper to the main power plane (VCC_TARGET_P3V3) and by replacing the jumper with an ammeter it is possible to determine the current consumption. To locate the current measurement
header, refer to Figure 1-1 .
Warning: Do not power the board without having the jumper or an ammeter mounted since this can cause SAMDA1 to be powered through its I/O pins and cause undefined operation of the device.
3.4. Standard Headers and Connectors
3.4.1. Xplained Pro Standard Extension Header
All Xplained Pro kits have one or more dual row, 20-pin, 100mil extension headers. Xplained Pro MCU boards have male headers while Xplained Pro extensions have their female counterparts. Note that all pins are not always connected. However, all the connected pins follow the defined pin-out described in
Table 3-5
. The extension headers can be used to connect a wide variety of Xplained Pro extensions to
Xplained Pro MCU boards and to access the pins of the target MCU on Xplained Pro MCU board directly.
Table 3-5 Xplained Pro Extension Header
Pin Number
1
2
3
Name
ID
GND
ADC(+)
Description
Communication line to the ID chip on extension board
Analog to digital converter , alternatively positive part of differential ADC
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Pin Number
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Name
ADC(-)
GPIO1
GPIO2
PWM(+)
PWM(-)
IRQ/GPIO
SPI_SS_B/GPIO
TWI_SDA
TWI_SCL
USART_RX
USART_TX
SPI_SS_A
SPI_MOSI
SPI_MISO
SPI_SCK
Description
Analog to digital converter , alternatively neg. part of differential ADC
GPIO
GPIO
Pulse width modulation , alternatively positive part of differential PWM
Pulse width modulation , alternatively negative part of differential PWM
Interrupt request line and/or general purpose I/O.
Slave select for SPI and/or general purpose I/O
Data line for two-wire interface. Always implemented, bus type.
Clock line for two-wire interface. Always implemented, bus type.
Receiver line of Universal Synchronous and
Asynchronous serial Receiver and Transmitter.
Transmitter line of Universal Synchronous and
Asynchronous serial Receiver and Transmitter.
Slave select for SPI. Should be unique if possible.
Master out slave in line of Serial peripheral interface.
Always implemented, bus type.
Master in slave out line of Serial peripheral interface.
Always implemented, bus type.
Clock for Serial peripheral interface. Always implemented, bus type.
Ground.
Power for extension board.
19
20
GND
VCC
3.4.2. Xplained Pro Power Header
The power header can be used to connect external power to the SAMDA1 Xplained Pro kit. The kit will automatically detect and switch to the external power if supplied. The power header can also be used as a power supply for external peripherals or extension boards. Care must be taken not to exceed the total current limitation if the on-board regulator for the 3.3V regulated output (85mA). To locate the current
measurement header, refer to Figure 1-1 .
Table 3-6 Power Header PWR
Pin number Name
1 VEXT_P5V0
2 GND
Description
External 5V input
Ground
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Pin number
3
4
Name
VCC_P5V0
VCC_P3V3_CON
Description
Unregulated 5V (output derived from one of the input sources: (1) Ext. 5V input, (2) USB Target, (3) USB
EDBG
Regulated 3.3V (output – used as main power for the kit)
Warning: If the board is powered from a battery source it is recommended to use the PWR header. If there is a power source connected to EDBG USB, the EDBG is activated and it will consume more power.
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