How to use MSDI Analog input channels with AMUX and eQADC?

[RegulusCheng]

Hi, everyone 

I am using RDVCU5775EVM with Simulink 2019b

I had some problems using the analog input channel of MSDI.

I had already tested the digital input channels of MSDI, so the CD1030 chip should work normally. But the user manual of CD1030 didn't say much about the AMUX function, so I don't know if I operate correctly.

I noticed that the User Guide of RDVCU5775EVM mentioned that the main chip uses eQADC channel ANA0 to receive the AMUX input of CD1030, so I just configured the eQADC modules to ANA0 and use it as a normal analog input channel, however, the data I get keep at around 7640(DEC), and no matter what voltage I give it, the data don't change.

I wonder if any other configuration should be done with CD1030 MSDI chips. Please help me.

[RegulusCheng · Accepted solution]

I have solved this problem. Before reading first need to send control instructions to the CD1030 chip through SPI communication to specify the specific pin of AMUX output.
The SPI instruction consists of a 32-bit register, the specific definition of which can be found in the CD1030 datasheet.
After the pin is specified, the analog value can be obtained by reading the ANA0 channel through the eQADC module, with a reading limit of 3.3V. Inputs higher than 3.3V are read as 3.3V.

[RegulusCheng]

Here is my model, hope it may help.