ADAU1452 with USB Amanero384 and out with FIFO PCM1704 DAC
Hi!
My project ADAU1452 as two way crossover:
Input USB Amanero I2S out (MCK, LRCK, BCK, and DATA) to I2S in2 of ADAU1452 eval board.
I2S out1 and I2S out2 to FIFO(74HC164) boards then to PCM1704(only use LRCK,BCK, and DATA no need MCK).
1. Is it possible?
2. Do not connect MCK(value is 22.5792 or 24.576MHz) from Amanero or use this MCK as external oscilator for ADAU1452 eval board.
3. Have to use ASRC or no need
Thanks in advanced.
Le Thanh Son
Audio Signal Processors
adau1452
SigmaDSP Audio Processors
Hello Le Thanh Son,
1) Is it possible?
The ADAU1452 will take in I2S and output I2S so as long as these other parts can send and receive I2S it will work.
2) I do not know the Amanero part but with many USB parts, I would expect that the MCLK may go away when there is no USB connection active. It is not good for the ADAU1452 DSP to not have MCLK when it first powers up and also to have it come and go. It is asking for problems. So I suggest you use an external oscillator module or a crystal to clock the MCLK of the DSP. Then use the ASRCs to interface to the USB interface. This way you will always have a valid clock running the DSP core and you can easily adapt to sampling rate changes and drift in the USB signal.
3) I would use the ASRC for the USB input. It will simplify your design.
So why are you using a FIFO on the I2S output to the DAC? I could not find the PCM1704 datasheet on the TI site so I have no idea why this is needed.
Dave T
Hi Dave Thib,
Thank you very much for your reply.
1. It is clear
2. No use/connect MCLK from USB, use 12.88 oscillator on ADAU1452 EVAL BOARD, and then use ASRCs.
3. use FIFO for NOS(non oversampling) DAC
Le Thanh Son
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