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ADAU1701 Self boot

Question asked by sudoganesh on Apr 30, 2010
Latest reply on Jun 7, 2010 by BrettG

         I  just implemented the program to take input from ADC and output it on   DAC in SigmaStudio.But program  is not working.

         We are not using any Evaluation  board , we have made all the circuit ourselves .We have used the circuit  in application note AN-923(describing how to  use ADAU1701 in Self Boot) except for we are using  BC857 (instead of ZX5T953), EEPROM AT24C512, and crystal ABL-12.288MHZ-B2 (load capcitance=18pF).Also I have connected RESET and WB to DVDD.

          I am attaching all the  files generated by SigmaStudio, I am  using file Eprom.hex in IC2 folder to burn EEPROM which i generated  using this post.
          I am just merely  writing program in sigmastudio, i haven't configured any registers in sigmastudio because I think default value of registers will be  sufficient to run this program.
         Things I observe while testing circuit are
         When nothing is connected to connected to ADC, the voltage at ADC inputs and the DAC ouputs is 1.5V.When I vary voltage give to ADC input (with a 100K potentiometer), then  also the DAC  ouputs remain 1.5V.
         I am unable detect whether problem is in hardware or software. Is there anyway I can make sure the hardware is alright, any  particular testing method? and if problem is in software can you suggest us any simple test program?
         We donot want to use Write Back  feature.Where should we connect WB pin to?
         Also, what happens  if the voltage at the core supply is 1.75V instead 1.8V?