Dataman In-System Programming of IIC Serial EEPROMs

Dataman In-System Programming of IIC Serial EEPROMs
Application note for In-System Programming (ISP) of IIC Serial EEPROMs
Application note for In-System Programming
of IIC™ Serial EEPROMs
Version 05/2006
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Application note for In-System Programming (ISP) of IIC Serial EEPROMs
General overview of serial memories
There exist a lot of variations of serial programmable memories,
which can be divided by capacity (from few bytes to mega bytes),
manufacturing technology (EPROM, EEPROM, FLASH), organization (x8,
x16), package type (DIP, SOIC, TSSOP, MLF, SON, ...), pins count and
alignment, special features (protection against inadvertent writes), ...
so you should be familiar with the device to know its operation and
features before you start working with it.
Considering the ISP programming, the major aspect to sort serial
memories, is a type of used communication protocol:
– IIC™ (Inter Integrated Circuit),
– SPI™ (Serial Peripheral Protocol),
– MW™ (Micro Wire),
– JTAG (Joint Test Action Group).
This Application Note discusses the IIC serial EEPROM memories.
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Application note for In-System Programming (ISP) of IIC Serial EEPROMs
About IIC™ Serial EEPROMs
IIC is a type of bi-directional 2-wire bus for inter-IC control. Each
device connected to the bus is recognized by a unique address [A2, A1,
A0] which is transmitted as a part of control word and compared with
signal levels on hard wired pins (A2, A1, A0) of device.
The communication interface of IIC devices represents signals SDA
(Serial Data) and SCL (Serial Clock), which are internally connected as
open collector (open drain). It means, that SDA and SCL wires of IIC
bus needs to be driven with pull-up resistor (PU), to get ability to
provide H level.
Some IIC devices have HW write protection capability applicable on
device memory. While the WP (PRE, WC\) signal is active, the data
inside of protected area can not be altered. For further informations
about write protected address range, please refer to technical
specification of programmed EEPROM – Datasheet (DS).
VCC and GND are used to supply voltage connection.
Signals:
Pin name
VCC
GND
Function
power
WP (PRE, WC\)
A2, A1, A0
control
SDA
communication
SCL
Description
Signal level
device power supply
1.8–5.5 (V)
common ground
0 (V)
Write Protect
(PRotect Enable, Write Control)
H, L
device system address
H, L
data input/output,
open collector (open drain)
clock signal,
open collector (open drain)
L, Pull-Up
NC
–
not connected
–
DC
–
don't connect
–
Table 1. IIC device signals description
Pinouts:
Figure 1. Standard pinout
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Figure 2. Alternative pinouts
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Application note for In-System Programming (ISP) of IIC Serial EEPROMs
Adaptation of target system for ISP
Following text contains important notices related to correct ISP
connection of in-system programmed EEPROM.
Respecting this, may prevent you from undesirable signal interference
on pins SDA/SCL of programmer and target system which often results
in unsuccessful course of ISP operation.
Detailed information about ISP pin-driver capability and pins assign is
listed in control program PG4UW of programmers (see Figure 6).
target device
ISP connector
SDA
SDA+
SCL
SCL+
target system
*1
*1
target WP check only
target VCC check only
GND
C1
22n
VCC
GND
I1
*2
VCC
SDA
SCL
RP1
RP2
J1
J2
WP
GND
A0
A1
A2
GND
GND
Figure 3. Circuit design
SDA, SDA+, SCL, SCL+ – These pins have to be driven with pull-up
resistors RP1, RP2. Values must meet the IIC bus specification,
otherwise the device may have problems with signal level recognition.
(*1): The programmer can provide a "stronger" ("better L level")
SDA/SCL signals from ISP driver, by interconnecting of coupled signals
SDA, SDA+ and SCL, SCL+.
(*2): If you have RP1 and RP2 resistors too low (approx. below
1.5kΩ), the programmer is not able to provide the sufficient L level at
SDA/SCL pins, you have to isolate SDA and SCL signals of programmed
chip (by jumpers J1, J2, for example). At this case, the programmer
provides pull-up resistors for SDA/SCL pins (see Figure 3).
A2, A1, A0 – Device address on IIC bus, hardwired to desired level
H/L. control program provides an option to select this address which
have to be sent during communication (see Figure 5).
WP (PRE, WC\) – Write Protect pin, must be set to inactive level
while programming the device. The programmer uses this signal to test
the WP pin level before programming the chip.
VCC – Power supply for programmed device must be supplied from
target system. The programmer uses this signal only to test, if the
target memory is powered. You can omit to connect this signal, and
disable VCC sense.
GND – Common ground for programmer and target system.
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Application note for In-System Programming (ISP) of IIC Serial EEPROMs
Operating with device
Device operation options:
Most of the programmers offer an option to supply power for target
system. If you want to use it, you must set up at least basic
parameters. You can do it through menu Device Options <Alt+O> - in
next <Alt+O> (see Figure 4).
Voltage level limitation of logical H signal is derived from target
memory VCC, set in Supply voltage edit box (value 3300mV, Figure 4).
Figure 4. ISP target supply parameters setting <Alt+O>
If the programmed EEPROM have the A2–A0 address inputs, you
have to set the value in section IIC special parameters <Alt+O>,
according to device address A2, A1, A0 in system.
There exist a few devices which offer IIC address selection, and which
haven't implemented this option in control program. In this case,
programming algorithm has set combination A2, A1, A0 to [000]b.
Values quoted (in DS) as X (Don't Care) are also interpreted as [0]b.
In case of unfavourable communication conditions (longer wires,
interfering environment, interference between signal from programmer
and system...) you can decrease clock frequency used for
communication by steps defined in IIC bus specification. Default value is
set to maximum supported by selected EEPROM.
Figure 5. IIC special parameters setting <Alt+O>
For further description of ISP parameters, please take a look at menu
Help by pressing the <F1> key, while the window <Alt+O> is opened.
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Application note for In-System Programming (ISP) of IIC Serial EEPROMs
Device info (Ctrl+F1):
The following window contains reduced information from this
application note and details about pins assign for each programmer with
short description of circuit design (see Figure 6).
Figure 6. Device info
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Application note for In-System Programming (ISP) of IIC Serial EEPROMs
Good advices and troubleshooting
Connecting programmer to system:
Turn off power supply of system before
disconnecting programmer to/from system.
connecting/
Before starting an operation:
Before starting an operation with target memory, please make
sure, that the ISP cable is correctly connected to the target
system and programmer. Also make sure that no device is
inserted to ZIF socket of the programmer.
If you want to program the device, please make sure, that
signal WP (PRE, WC\) will not be active during the action.
Details about pins assign for each programmer and short
description of circuit design can be found in control program
(Device Info <Ctrl+F1>).
Device pins marked NC (Not Connected) or DC (Don't Connect!)
should be left unconnected. Also leave unconnected the pins of
ISP connector marked “Don't Connect!”.
Correctly selected values of pull-up resistors on SDA/SCL
wires of IIC bus can provide reliable signal level recognition (for
both, programmer and system) and successfulness of desired
operation. Please make sure, that your design meets IIC bus
recommendations (see also Adaptation of system for ISP,
page 4).
If something went wrong:
If programmer reports signal interference error, may be, a
signal interference occurred between programmer and system.
Please make sure, your design meets IIC bus recommendations.
Check the minimal value of PU resistors on SDA/SCL wires from
programmer's point of view (in order to programmer be able to
put L level on the pin).
If you haven't yet interconnected the signals SDA, SDA+ and
SCL, SCL+ of ISP connector, please do that, and try to repeat
desired operation.
If operation result still reports errors, please try to decrease
clock frequency and repeat last operation (<Alt+O>).
Be aware, that longer ISP cable (longer than 20cm/0,7ft) may
cause an unpredictable signal interference. Make sure you are
using correct cable.
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Application note for In-System Programming (ISP) of IIC Serial EEPROMs
Used abbreviations
AN – Application Note.
DIP, SOIC, TSSOP, MLF, SON – type of device package.
EEPROM – (Electrical Erasable Programmable Read Only Memory) type
of memory.
HW WP – (Hardware Write Protect) write protect feature. It's realized
via appropriate signal level on device pin, not by setting some WP
register.
IIC™ – (Inter Integrated Circuit) type of communication protocol,
communication bus, IIC–bus™ is registrated trademark of Philips
Semiconductors Corporation.
ISP – (In System Programming) programming of device inserted into
system.
JTAG – (Joint Test Action Group) an acronym for Joint Test Action
Group, is the usual name used for the IEEE 1149.1 standard for Test
Access Port and Boundary Scan, primarily used for testing integrated
circuits, but also useful as a mechanism for debugging embedded
systems.
MW™ – (MicroWire) type of communication protocol, MICROWIRE™ is
registrated trademark of National Semiconductor, Corp.
Open collector/drain – type of used interface, collector/drain of
transistor creates an output. In order to be output able to set H level,
the device needs to be supplied with constant PU on the pin.
Pull–Up (PU)/Pull–Down (PD) – increase/decrease of signal level
by connecting PU/PD resistor to VCC/GND.
SPI™ – (Serial Peripheral Interface) type of communication protocol,
SPI™ is registrated trademark of Motorola Corporation.
ZIF – (Zero Insertion Force) type of socket, used in programmer for
better manipulation with device.
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Application note for In-System Programming (ISP) of IIC Serial EEPROMs
Revision history
05/2006:
Changes of figures:
– Fig. 3 Circuit design – minor changes
– Fig. 6 Device info– minor changes
06/2005:
Added sections:
“Revision history” – this section.
Other:
– added abbreviation “AN”,
– changes in “Device operation options” section
–
02/2005:
Changes of terms:
“target device” to AN specific “serial EEPROM” or “EEPROM”,
– “target application” to “target system”.
Changes of figures:
– Fig. 3 Circuit design – added comment marked as “(*2)”,
– Fig. 4 ISP target supply parameters setting – shows different values
selected in edit box.
–
01/2005:
Initial Release.
Version 05/2006
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