DS90UB954-Q1: T_HS_PREPARE is longer than d/s max

Betty Guo

Part Number: DS90UB954-Q1

Hi team,

customer test UB965, and the SOC can't reveive the MIPI signal. customer capture the output of 954 find the MIPI time is doesn't match d/s

in datasheet, the T_HS_PREPARE is 40+4ul ~85+6ul, actually, customer measure the T_HS_PREPARE IS 133ns, below is waveform.

we need your help on below items:

1. how to adjust the MIPI signal time to match the d/s. if can't adjust, why the T_HS is longer than d/s

2. does the T_HS_PREPARE can affect SOC to reveive signal?

3. could you give guiance to debug? thanks.

CLK: green

Red--DP(CSI D3P) ; Yellow--DN(CSI D3N)

0 Betty Guo over 4 years ago

Hi team,

I find in datasheet page46, have a code for CSI-2 timing parameters. does 0xB0/0xB1/0xB2 can adjust the MIPI timing?

if yes, how to adjust? I didn't find description about reg 0xB0/0xB1 and 0xB2. In customer application, the CSI-2 transmitter is 400Mbps

thanks.

0 Casey McCrea over 4 years ago in reply to Betty Guo

Betty,

Please follow the instructions on page 46 of the datasheet to set the MIPI timing parameters for 400Mbps. The code example is given on that page

Best Regards,

Casey

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