I am designing a system with a AD1940 controlled off a Pic24F microcontroller.
For testing the hardware, I have a simple 4 in 4 out schematic, no processing, no volume controls. Straight in straight out.
I a have a 12.288 MHz master clock, with 4 inputs input 48 k 24 bit left justified.
The board is 4 layers and the signal integrity looks good.
I verified I can read and write to the SPI Port. However, after initializing everything, downloading the code, I get nothing on any of the serial outputs.
The only thing I have found odd, is when read from the DSP Core control Register ( 2642), I get a one in bit 14 which is a reserved bit. The one is also set for bit 9. If I write a 0x00 to (2642) , when I read it back , there still is a one in bit 14. I can read and write to other registers.
Does anyone know what these reserved bits are for?
So far I can not figure out hat is wrong whether it is software or hardware.
Does anyonw have any good advice ?