Hi expert,
We meet an MPO1 output issue as below.
The path AUXIN1 ->DIT -> MPO1 is verified successfully, but the path I2S input(ADC) -> SPDIF output failed
MPIO_C (I²S Input, AUXIN1)
↓
DIT (PCM9211 SPDIF Transmitter)
↓
MPO1 (SPDIF Output)
Customer want to configure 9211 according to this process, but I2S->MPO1 has been unable to measure the spdif signal(no output)
The current register configuration is as follows:
PCM9211 Read 34h = c4.
PCM9211 Read 23h = 03.
PCM9211 Read 20h = 00.
PCM9211 Read 26h = 89.
PCM9211 Read 31h = 0a.
PCM9211 Read 28h = 07.
PCM9211 Read 61h = 10.
PCM9211 Read 63h = 00.
PCM9211 Read 30h = 14.
PCM9211 Read 25h = 3f.
PCM9211 Read 2Ah = 00.
PCM9211 Read 2Bh = 00.
PCM9211 Read 6Eh = 0f.
PCM9211 Read 6Fh = 40.
PCM9211 Read 70h = 00.
PCM9211 Read 6Bh = 44.
PCM9211 Read 60h = 44.
PCM9211 Read 78h = dd.
PCM9211 Read 37h = 02.
1.With only one input source (MPIO-C), this configuration also includes IIS output (main output). The measurement of main output is normal, so it can confirm that the input is not a problem.
2.Using a fiber opt source and AUXIN4 as input, changing the 0x60h register to 0x11 can achieve spdif output from auxin4 to mpo1. The spdif signal is tested to be normal.So this configuration, MPO1 as spdif output, is also configured correctly.
But even when the 0x60h register is 0x44, MPO1 pin cannot detect the spdif signal.
Input clock = 24.576MHz active crystal oscillator (only connected to XT1)
Please help suggest the possible issue and register configuration/check points
System block

