Hello,
in our design we have setup with DS90UB936 and DS90UB935. Connection is over coaxial cable, with PoC.
Both devices are set to CSI-2 Synchronous mode - DS90UB935 MODE=0, DS90UB936 MODE=4.
We are having problem with getting link lock stable, while checking status in register 4 of DS90UB936, we observe changing values between 0xd3 and 0xdf
Can you please advice some steps to proceed to find out root cause of this issue ?
Just for reference, here is registry dump from DS90UB936:
locked:
0000: 60 00 1e 20 df 00 00 fe 1c 10 7a 7a 83 b9 00 7f
0010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 04 02
0020: 20 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0030: 00 00 00 21 40 00 00 03 00 00 00 01 14 6f 00 40
0040: 00 a7 71 01 00 00 00 00 00 00 00 12 01 38 3a 00
0050: 00 00 00 02 00 08 a8 00 5e 00 00 30 32 76 00 00
0060: 00 00 00 00 00 76 00 00 00 00 00 00 00 7c 88 88
0070: 2b 2c e4 00 00 00 00 c5 00 01 0f ff 20 00 00 00
not locked:
0000: 60 00 1e 20 d3 00 00 fe 1c 10 7a 7a 83 b9 00 7f
0010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 04 02
0020: 20 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0030: 00 00 00 21 40 00 00 03 00 00 00 01 14 6f 00 40
0040: 00 a7 71 01 00 00 00 00 00 00 00 12 01 30 3a 00
0050: 00 00 00 02 00 00 00 00 5e 00 00 30 32 76 00 00
0060: 00 00 00 00 00 76 00 00 00 00 00 00 00 7c 88 88
0070: 2b 2c e4 00 00 00 00 c5 00 01 0f ff 20 00 00 00
PoC network is implemented the same way as in reference schematics, with exactly same components.
Voltages on MODE pins are checked - DS90UB935 is 0V, on DS90UB936 it is 1V.
REFCLK on DS90UB936 is 25MHz from quartz oscillator, also check, there is correct frequency.
Regards
Arkadiusz
