LMH0318: Reading regs via I2C

Greetings,

Please follow link below that describes RAW format in details:

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/897323/faq-lmh1297-programming-raw-command-syntax-explained/3317304#3317304

Regards ,, Nasser

Hallo Nasser,

Thanks for your answer.

Unfortunatly the link you provided me do not answer the question.

Im asking for the details of I2C transaction to read the register.

The link talk about write transaction only and do not provide any I2C details.

Regards.

Greetings,

Glad you are able to do a write operation.

To do a read operation, you would use the same format as write but with a mask of 0x00.

Regards ,, Nasser

Hallo Nasser,

unfortunately your advice is still not solving the problem.

As an example I try to write and then readback the written value on the OUT0_VOD channel register (address 0x80), but I cannot readback the previous written data.

This is the transaction issued:

RAW FF 04 04           //Select Channel Registers
RAW 80 60 F0           //Write the OUT0_VOD reg to 0x60

RAW FF 04 04           //Select Channel Registers

RAR 80 FF 00           //Read the OUT0_VOD Registers

When I read I get 0x80 (I was expecting 0x60).

In term of SPI character the read transaction is don In this way:

S DevAddr Wr [A] Register Address [A] Register Content [A] Register Mask [A] P S DevAddr Wr [A] [Register Content] NA

With real data

S 0x19 Wr [A] 0x80 [A] 0xFF [A] 0x00 [A] P S 0x19 Wr [A] [0x80] NA

please see the attached captured transaction:

If you can send the details of the I2C read transaction I'm sure we can succesfuly close this topic.

Regards.

Here a zoom of the last transaction:

If you need others detail or test, please let me know.

I also try a different I2C transaction style, probably more inline with the SNLS508 page 20.

This time I get back 0xFF, again a wrong value.