Table of Contents

V-DIO EL502 EEPROM Programming

The newly manufactured EL502 Mezzanine cards do not contain any data in their EEPROM yet. A Raspberry Pi and a custom made cable are used to programm the EEPROM.

Resources

The code of this project is under version control in a Git repository whose upstream is: https://git.gsi.de/BEA_HDL/V_DIO_EEPROM_Programming

How to program the EEPROM

 I2C connection

Raspberry Pi Raspberry Pi Mezzanine Mezzanine
pin number signal name pin number signal name
1 +3.3 V 1 +5 V
3 SDA 3 SDA
5 SCL 2 SCL
6 GND 26 GND

Programming with individual serial numbers

Alternative static programming and verification scripts

Programming

This will program the content of src/eeprom_content.csv to the EEPROM.

Verification

This will create an output file src/eeprom_content_readback.csv.

You can compare it to the desired content using diff eeprom_content_readback.csv eeprom_content.csv.

Testing the IO expanders

The six IO expanders on the EL502 Mezzanine can be accessed via the same I2C bus. The following commands can be used:

Listing the available I2C devices

i2cdetect -y 1 will list all available I2C devices on the I2C bus /dev/i2c-1

The output on the EL502 is the following:

0 1 2 3 4 5 6 7 8 9 a b c d e f

00: -- -- -- -- -- -- -- -- -- -- -- -- --

10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

20: 20 21 22 -- 24 25 26 -- -- -- -- -- -- -- -- --

30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

50: 50 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

70: -- -- -- -- -- -- -- --

The devices with the addresses 0x20, 0x21, 0x22 are the IO expanders on the top side. The devices with the addresses 0x24, 0x25, 0x26 are the IO expanders on the bottom side. The device with the address 0x50 is the EEPROM.

Writing registers

Via single CLI accesses

E.g. i2cset -y 1 0x20 0x02 0xff will write the value of 0xff to the register 0x02 on the device with the I2C address 0x20.

Via a script

This will program the content of src/io_expander_config.csv to the registers of the IO expanders.

Reading registers

Via single CLI accesses

E.g. i2cget -y 1 0x20 0x02 will read the value of the register 0x02 on the device with the I2C address 0x20.

Via a script

This will print all the register values of the IO expanders.