Sigmastudio multiplexer problem (ADAU1452)
Hi,
I have a custom board with ADAU1452 and a uController. The DSP has 3 digital inputs (I2S), which are selected by the uC through ADAU1452's input pins. In sigmastudio there's a multiplexer that is controlled by GPIO pins. Everything runs fine, except that the multiplexer only switches between the first 2 input ports only. The readback block connected to the updown LUT with look-up table shows that the block works fine, however, the multiplexer refuses to work as expected. I don't understand what the problem is. I have attached sigmastudio's schematic. Any input would be greatly appreciated.
Thank you!
Audio Signal Processors
adau1452
SigmaDSP Audio Processors
This is my LUT
I suspect a bug in Sigmastudio (V4.2). Since the updownLUT has the correct number, the mux should work fine. But the mux works fine only for its default 2-input, so maybe something is wrong with the "grow algorithm" thing.
Hello kpapi1,
Fortunately, this difficulty is not a bug and is easily remediable. The Buffer Gate feeding the Mux's control input via Alias1 can only output a binary "1" or "0" -- thus the Mux never switches to its higher channels. Try replacing the Buffer Gate with this arrangement:
Multiplying the LUT output by a "1" in 32.0 format converts its decimal (8.24) format to the integer (32.0 format) required by the Mux control input.
Best regards,
Bob
Hi Bob,
Thank you so much for your reply. I just tested it and it works perfectly!!!
Kostas
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