I am interfacing Pmod AD5 form Digilent which has a AD7193 chip in it with FPGA. To start with, I have successfully written to the mode and configuration register and read back the values of these registers. I have also tested the ADC by giving some constant voltage inputs and I noticed that I was getting some error of the order 10^(-3). So I decided to do the calibration. I first tried doing the internal zero scale calibration.
I am writting x080010 to Mode register
then x000110 to Configuration register ...(just to start the code)
Then I am again writting x880010 to Mode register ....(For Internal zero scale calibration)
and using polling to check when RDY' goes low. ...(For RDY' I am reading the status register's MSB bit)
But the RDY' bit never returns low. The status register reads 10000000 in binary.
I am not giving any inputs to the ADC.
I have gone through the other discussions related to the calibration on this forum.
I am pretty much stuck at it for a long time.
Please help me out