After reading a couple of earlier postings about getting this board to run at 96 or 192kHz, fs I learned it is first necessary to configure SPI communications. My plan of approach is to first establish the SPI link with the ADAU1442 on the EVAL board and then make the necessary changes to permit Sigma Studio to configure the AD1938 codecs on the same board ( for fs > 48 kHz ). So far have not been able to get the 1442 SPI connection established.
Here is what I've done so far :
1) Set switch S4 to "SPI" position. ( SPI mode NOT I2C )
2) Set switch S2 (pole #8) to "OPEN" or "OFF" ( Allows CDATA/ADDR1 line to move i.e. NOT pulled to ground by switch )
3) Leave switch S2 (pole#7) "CLOSED" or "ON" ( This should set ADAU1442 SPI chip address to : 0000000 )
4) Note : Both AD1938s are in Eval Board factory configuration ( i.e. Standalone Mode )
5) In Sigma Studio Hardware Config : USBi block ( SPI 0x1ADR0 ) is connected to ADAU144x block.
With fs set at 48kHz, no longer am able to get an analog signal through the board ( this worked with I2C comm. )
DSP Read-back block connected to a DC source only reads Zero.
With DSP Read-back block running in continuous read mode ( at say 100 ms ) I can see clean pulses on CLATCH_1442, CCLK/SCL, COUT/SDA and CDATA.
Also, yellow SPI LED on ADUSB2Z board flickers.
Any help will be appreciated - Thanks.