Hi TI,
I'm using the TLV320AIC3256 in a design that's connected to two digital microphones multiplexed onto the same input line. My microphone specifications say that I can clock them between 1 and 3MHz. I'd like to sample the audio at 48KHz into miniDSP_A and then pass it on to the OMAP via I2S.
I'm having trouble determining all the different clock and divider settings that I need to use. Here's what I think that I've figured out so far:
- Our MCLK input at the codec is set to 19.2MHz. We pass this through the PLL (P=R=1, J=4, D=4800) and use it as codec_clk_in, which is now ~86MHz.
- It seems that the only clock that can be used for the digital mics is adc_mod_clk. Therefore we get that to 3.072MHz by setting NADC=2 and MADC=14.
- Right now we have AOSR=64 to get a final ADC f_s of 48KHz.
- We're decimating by 4x in the DSP and just hooking it directly up to I2S_out.
This seems like it should be right, but the audio is coming through very garbled. I'll attach a sample of the audio once I find the upload button.
I'd appreciate any help with determining what clock settings we should be using. Thanks!
