DS90UB954-Q1: Register settings about DS90UB954 and DS90UB953

pls check:

1. forward channel rate? 

2. what is th reg. 0x4c/4d/4e/55/56/73/74/75/76 (pls check d/s on these registers, you can set the assigned port, then you also need read the reg. to clear the initial values for correct link error record)

regards,

Steven

Hello Steve

1. Our REFCLK is 25Mhz ,Mode is Non-Synchronous external clock .according to datasheet ,forward channel rate is 2Gbps?

2. The register information is as follows:

0x4c: 0x1
0x4d: 0x13
0x4e: 0x4d

0x55: 0x0
0x56: 0x0

0x73: 0x4
0x74: 0x61
0x75: 0x9
0x76: 0x7e

Hello

Can you measure the the FWD channel data rate and send us some scope plots showing what the data rate is?

Thanks

Vijay

Hello

Sorry we do not have professional equipment to measure the eye diagram of FWD channel data rate. Only use a common oscilloscope to measure the following pictures,I don't know if it helps.

Hi

     Very difficult to say but it does look like 2Gbps. 

Can you please also read Reg0x04? Is the LOCK pin high?

Thanks

Vijay

Hello,

When you say REFCLK is 25MHz, do you mean REFCLK on the 954 side or CLKIN on the 953 side? For non-synchronous external clock mode the CLKIN on the 953 side is what defines the FC rate.

Best Regards,
Casey 

Hello

Our Lock pin is high and stable in Non-sync mode,otherwise we can't set the 953 side register.

thanks

Hello，

Yes, the REFCLK I mentioned is the REFCLK on the 954 side. Thank you for your suggestion. I will try to add a clock on the 953 side.

Thanks.

Hello Casey,

We have added a clock of 48Mhz to the CLKIN pin of 953,  and still can't get the correct mipi data. Is there any other register that I need to configure?

Or if possible, can you provide us with a list of register configurations for 953-954 in synchronous mode? We want to try whether the synchronization mode is feasible.

Thanks.

hi, 

since the reg. 0x73/74/75/76 has data, you can decode that it is: 2430bytes *1121 line count.so it sounds the link is correct,pls check:

1. what is the camera format? it is 1920*1080@30Hz? 

2. what is the mipi rata between 935 and sensor? if you use 2Gbps mode, pls secure that the mipi total rate is <1.6Gbps, or else it could introduce the video data loss.

3. can you read 0x73/74/75/76 for more times? the returned values are same?

best regards,Steven

Hello Steven:

1, 2592*1536@30fps

2, MIPI datarate is 594mbps/lane , I want to increase to 4Gbps, but I don't know how to operate in asynchronous mode.

3,Yes ,it's the same, 

0x73: 0x4
0x74: 0x61
0x75: 0x9
0x76: 0x7e

Thanks.

Hello Steven

1. When we use synchronous mode on both sides, 953 and 954 cannot be locked. We don't know why.

2. Which is table 7? Is it table 6? We are trying to find a 104Mhz clock connected to the CLKIN pin of 953 to try the asynchronous external clock mode.

Thanks

tiancheng,

so now the issues are:

1. in sync. mode, 954 is unlocked? please measure the unlock signal to us, it is unlocked occationarily or always?

2. yes, it is table6. in the aysnc. mode with 100MHz, what is the result? does it work normally or not? at this mode, the fpdlink rate is up to 4Gbps.

regarsd,

Steven