SK-TDA4VM: EEPROM access

Jaecheon Yoo

Intellectual 746 points

Part Number: SK-TDA4VM

Tool/software:

Hi experts,

I saw EEPROM data in User manual.

but if we dump eeprom like this, there seems no data in it.
IS IT correct access?

root@tda4vm-sk:/opt/edgeai-gst-apps# i2cdump -f -y 0 0x51
No size specified (using byte-data access)
     0 1 2 3 4 5 6 7 8 9 a b c d e f    0123456789abcdef
00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
20: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
40: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
90: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
c0: ff ff ff ff ff ff ff ff ff 00 ff ff ff ff ff ff    ................
d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................

2) If there is no data in EEPROM, what happens in SK-TDA4VM?

3) Please share command to write data to EEPROM data.

over 1 year ago

+1 Takuma Fujiwara over 1 year ago

TI__Guru 51323 points

Hi Jaechong,

Some repeat from our previous threads but...

There is some dependency in U-Boot and kernel for loading in the correct board information like device tree, which I think EEPROM is being used to identify the board. Theoretically, it should be possible to skip EEPROM if you change the uEnv.txt file in the boot partition to set and load in the correct environment variables and overlays. Additionally, you may need to do something similar to what a customer is doing for AM64x: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1359198/am6442-how-to-bypass-the-eeprom-checking-procedure.

Also, it seems Linux is struggling to read EEPROM, but U-Boot can read EEPROM. While booting, press any keys to stop U-Boot and run "i2c dev 0" and "i2c md 0x51 0x0.2 0x100" to read EEPROM which should have something like:

Fullscreen 4540.eeprom_sk_tda4vm.txt Download

U-Boot 2023.04-g71b8c840ca (Nov 27 2023 - 08:55:35 +0000)

SoC:   J721E SR1.1 GP
Model: Texas Instruments J721E SK A72
Board: J721EX-EAIK rev A1
DRAM:  4 GiB
Core:  121 devices, 34 uclasses, devicetree: separate
Flash: 0 Bytes
MMC:   mmc@4fb0000: 1
Loading Environment from nowhere... OK
In:    serial@2800000
Out:   serial@2800000
Err:   serial@2800000
am65_cpsw_nuss ethernet@46000000: K3 CPSW: nuss_ver: 0x6BA00101 cpsw_ver: 0x6BA80100 ale_ver: 0x00293904 Ports:1 mdio_freq:1000000
Net:   eth0: ethernet@46000000port@1
Hit any key to stop autoboot:  0
=>  i2c dev 0
Setting bus to 0
=>  i2c md 0x51 0x0.2 0x100
0000: aa 55 33 ee 01 37 00 10 2e 00 4a 37 32 31 45 58    .U3..7....J721EX
0010: 2d 45 41 49 4b 00 00 00 00 00 41 31 30 31 31 32    -EAIK.....A10112
0020: 30 31 41 31 00 00 30 31 30 31 32 31 32 32 00 00    01A1..01012122..
0030: 00 00 00 00 31 33 33 32 11 02 00 60 7d fe ff ff    ....1332...`}...
0040: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0050: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0060: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0070: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0090: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00c0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
=>

If you would like to write to EEPROM, then please reference following logs in which I:

Read 0x100 registers starting from 0x0 from I2C address 0x51 (address of EEPROM)
Write to 0x51 (EEPROM), to the register 0x0 on the EEPROM, the value of 0xab, which is length 1
Read 0x100 registers again to verify the first register content changed from default 0xaa to 0xab

Fullscreen changing_eeprom_sk_tda4vm.txt Download

=>  i2c md 0x51 0x0.2 0x100
0000: aa 55 33 ee 01 37 00 10 2e 00 4a 37 32 31 45 58    .U3..7....J721EX
0010: 2d 45 41 49 4b 00 00 00 00 00 41 31 30 31 31 32    -EAIK.....A10112
0020: 30 31 41 31 00 00 30 31 30 31 32 31 32 32 00 00    01A1..01012122..
0030: 00 00 00 00 31 33 33 32 11 02 00 60 7d fe ff ff    ....1332...`}...
0040: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0050: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0060: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0070: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0090: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00c0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
=> i2c mw 0x51 0x0 0xab 1
=>  i2c md 0x51 0x0.2 0x100
0000: ab 55 33 ee 01 37 00 10 2e 00 4a 37 32 31 45 58    .U3..7....J721EX
0010: 2d 45 41 49 4b 00 00 00 00 00 41 31 30 31 31 32    -EAIK.....A10112
0020: 30 31 41 31 00 00 30 31 30 31 32 31 32 32 00 00    01A1..01012122..
0030: 00 00 00 00 31 33 33 32 11 02 00 60 7d fe ff ff    ....1332...`}...
0040: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0050: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0060: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0070: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
0090: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00c0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
00f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
=>  i2c md 0x51 0x0.2 0x100

Regards,

Takuma

Processors

Processors forum

SK-TDA4VM: EEPROM access