Download GPIO Demo module System Reference Manual - Techno

GPIODemo_SRM
Module v0.4
Fig 15 – EEPROM for Module Identification
As shown on figure 15 the hardware sets the A2 address configuration bit to "1", thus only small EEPROMs will
answer to address "0xA0 / 0xA1", while bigger ones answer to address "0xA8 / 0xA9".
In addition to the address differentiation for the EEPROM size access to EEPROM memory requires use of a
particular "EEPROM select" mechanism.
The EEPROM on the DomoTab modules are used to identify the module function, name, version, and possibly
store the task code for the OS to communicate with the module. Many modules can be plugged at the same time
on a single device, and the device needs a mechanism to read only one EEPROM at a given time to identify the
module physical position when the device has many UEXT connectors. This is done using the SPI Slave Select
signal from the UEXT connector. The I2C clock signal (SCL) is not transfered to the EEPROM memory chip when
the SPI SSEL signal is not active (LOW).
This is true even if the module is not plugged on a UEXT connector. Thus before any access to the EEPROM
memory one must activate the SPI SSEL signal (put the GPIO0_15 pins in LOW output state).
Refer to sample code for an example of how this is done in software and for the routines to read and write
EEPROM memory.
4.2.3
Temperature sensor
Fig 16 – Temperature sensor
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