TLA2528: I2C cannot get ADC converted data

Part Number: TLA2528

Tool/software:

Hi, Expert,

I am struggling to read back the TLA2528 ADC converted data (the full two bytes) these days. I looks like I can only read back one byte of the converted data, but the second byte is always 0xFF.  Can you please help me to see where might be wrong?

1. The I2C single register write and single register read can work in my setup.

2. The ADC converted data (for example on AIN0) cannot be read out. I can only read only the first byte(0x74), but the second byte is always 0xff. Below is my measured timing diagram which is referenced from the Figure 8 in the datasheet:

3. If I set FIX_PAT = 1 in register 0x2, then I always read back 0xA5, 0xFF. It looks like the first byte 0xA5 is correct, but the second byte is always 0xFF.

Can you please provide me some ideas where might be wrong? Appreciate so much.