ADS122C04: reading 2 bytes instead of 3

Adding screenshot of data exchanges : 

Hi Benoit,

Welcome to the E2E forum. I apologized for the late response.

Did you enable any data integrity check or data counter? you are getting total 6 bytes data, see them in the following image.

Best regards,

Dale

Hi, I have the same issue. A Ads122C04 marked 122C is acting like a 112C04. Whatever the CRC, the inverted result or bare raw data...

I think there are 6 bytes because the master asks 6 bytes of data, so there are 6 clock cycles.

There is a 0x0000 data and a 0xFFFF inverted data, it seems obvious.

Hi Benoit, Cedric,

I would suggest you do the following test:

1. Check the output data with DEFAULT configurations (normal mode, internal Vref, counter off, no integrity check and so on)
2. If the check in step 1 is correct, then you can change a register configuration, then read it back to double check if your register writing is successfully. Note: change the register step by step, for example, just enable CRC to check.

If you did not buy this device from TI's official distributor or directly from TI, that will be a different story. A lot# and top mark on the device may be helpful to check.

Regards,

Dale

Hi Dale,

I have tested with a newly bought one and I have 3 bytes as expected. It seems that we have a bad marked device serie. Is it possible? This is a picture of a bad one.

Hi Cedric,

I would suggest you contact the distributor where you bought that device for failure analysis and investigation. 

Best regards,

Dale