Interfacing to TDA1543A

[Ian Wilson]

Trying to get an interface between a PIC and a TDA1543A working. I assume that the 3 input pins for the "A" version are the same as the non-"A" version (data/bit clock/select). These 3 pins are hooked up to PIC outputs. The L/R outputs are connected to 1k resistors to ground, for the moment.

I measure 2.2v on the reference pin, and 1v on the outputs. Seems sane, at least.

I know that the TDA1543A takes a Sony input format. I'm trying a simple test to set the L or R word by setting a level on the data input and applying a number of clocks. Then I change the select line, the input value, and apply the same number of clocks. I would expect this to fill one channel with all 0's and the other with all 1's.

Regardless of what I try, however, the outputs remain constant at +1v. Is my assumption about the input pins incorrect? Any ideas? I can try things out easily enough; just out of ideas for the moment.

Thanks,

--ian