< I am using 8 ADS1256 adc's in a board and through FPGA reading the output to microcontroller on multiplexing basis
but whatever command I give ADC gives output as 00 even no data is coming on DOUT pin.
even I am not able to read configuration registers > <please give some hints to solve this problem>
"I am using 8 ADS1256 adc's in a board and through FPGA reading the output to microcontroller on multiplexing basis"
As Per says, you have far too many unknowns here!
Start simple: can you get your code to read a single ADC with no FPGA, multiplexing, or other stuff to confuse the issue?!