TC9204M
Preliminary Data Sheet
10 EEPROM Interface
TC9204M can be configured using a serial EEPROM device type AT24C02A (2048 bits organized as 208
pages of 1 byte each). With this device the manufacturer can deliver a pre-configured system to their
customers while the customers can reconfigure the system and retain their preferences. TC9204M also
provides a virtual internal EEPROM mode, which enables the programming entity to write the
configuration data directly into the chip, without using the external EEPROM. In this mode the
configuration data is lost after reset procedures.
The TC9204M is able to operate without this device and can make effective use of its features using only
the pin configuration interface. The EEPROM configuration provides additional features and it can
override all pin interface settings offering a jumperless configuration mode. For this reason equivalent
EEPROM settings can be found for every configuration pin.
A validation bit is provided for each one of the EEPROM Configuration Registers. A dedicated Validation
Register is reserved for this purpose and corresponding bits from this register must be set in order to
enable the desired EEPROM configurations.
The EEPROM configuration information is accessed by the TC9204M after each reset procedure.
10.1
Reprogramming the EEPROM for reconfiguration
If the ‘Reset’ pin is hold Low the TC9204M‘s EEPROM interface will go into high impedance state. This
feature enables easy reprogramming of the EEPROM during installation or reconfiguration.
The EEPROM can be reprogrammed using an external parallel port. A dedicated signal from this port
can be used to hold the RESET pin Low. Once the TC9204M interface pins have got to the high
impedance state the EEPROM can be programmed by the parallel port trough the SDA and SCL pins.
To enable the AT24C02A device to be accessed by the TC9204M its page address input pins must be
hardwired to ‘0’. For virtual EEPROM mode the programming can be done using the same AT24C02A
byte write protocol but page address bits must be “100” (A2 downto A0).
EEPROM
Parallel
Port
SDA
SCL
Reset
TC9204M
Confidential.
23/49
July 29, 2003
Copyright © 2003, IC Plus Corp.
TC9204M-DS-R05
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