• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 452 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DS90UB954-Q1: DS90UB954-Q1: UB954/953 support 2mp 120fps ?

SVL SVL
Prodigy 130 points
Part Number: DS90UB954-Q1
Other Parts Discussed in Thread: ALP

Hello.
I am using UB954/953 together with the IMX290 sensor, I have successfully configured the serializer and deserializer in 4 line mode, I am getting images on my jetson TX2 with a frame rate of 30/60 12bit.
I tried to get a 120fps 10bit image but so far I haven't been able to.
According to the datasheet sensor it requires 891 Mbps / Lane and 4 Lane for 120fps 10bit.
891 * 4 = 3564Mbps
According to datasheet 954/953, the bandwidth is 4.16 Gbps, which is more than the sensor needs.
I checked the CSI signal at the output of UB954 using an oscilloscope, the signal is on all 4 lines, the signal responds to the dimming of the sensor, unfortunately I can not check the signal corectly but I'm sure the signal reaches the jetson TX2 and responds to change the sensor image.
Where does the figure of 4.16 Gbps in the datasheet come from?
Do I understand the possibilities of 954/953 correctly?
Is it possible to get 120fps 10bit images from IMX290 via 954/953?
Thanks.

  • 0
    TI__Expert 5480 points

    Hello, 

    What reference clock are you using on the 954? Is it a 25 MHz or 26 MHz clock? The forward channel is derived from the refclk frequency. The forward channel link rate can support up to 80%  of the link rate of CSI-2 bandwidth. Are you sure you are not having a buffer overflow here? What does register 0x4e and 0x35 read? 

  • 0 in reply to Sally Cheung95
    Prodigy 130 points

    Thanks for your reply.
    I use devkit ub954 / 953 and according to the scheme refclk = 25 MHz, ALP alternately shows refclk 25 MHz or 24 MHz.
    Do I need to accurately measure refclk or change refclk to 26 MHz?
    0x35 is almost always 0x01
    the values ​​of 0x4e change very quickly at the beginning of the video signal transmission, I do not have time to record all the values, I received the values ​​0x04, 0xed, 0xcd, 0x0c.
    As far as I understand there are no buffer errors.
    At 30/60 fps I sometimes got a value of 0xED in register 0x4E at the beginning of the video signal transmission, it did not interfere with getting the image, because of this it seemed to me that the errors relate to the first few frames of the image so I stopped taking them into account.
    Now when transmitting 120 fps video, the value of the 0x4E register is 0x0C most of the time, sometimes I see 0xED.
    Dump registers ub954 before the start of video transmission:

         0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 60 00 1e 20 d7 01 00 fe 1c 10 7a 7a ad 09 28 7f    `.? ??.???zz??(?
10: 00 00 00 00 00 13 00 00 00 00 00 00 00 00 04 00    .....?........?.
20: 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00    .?..............
30: 00 00 00 01 40 00 00 00 00 00 00 01 14 6f 00 40    ...?@......??o.@
40: 00 a7 71 01 00 00 00 00 00 00 00 12 01 11 04 64    .?q?.......????d
50: 00 00 00 03 00 00 00 00 5e 82 00 30 30 34 00 00    ...?....^?.004..
60: 00 00 00 00 00 34 00 00 00 00 00 00 00 7c 88 02    .....4.......|??
70: 2b 2c e4 00 00 00 00 c5 00 01 00 00 20 05 00 00    +,?....?.?.. ?..
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
a0: 02 0f 00 00 08 18 00 00 00 00 00 00 00 00 00 00    ??..??..........
b0: 08 14 3f 08 25 00 18 00 8c 33 83 74 80 00 00 00    ????%.?.?3?t?...
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
d0: 00 43 94 02 60 f2 00 00 00 00 00 00 00 00 00 00    .C??`?..........
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
f0: 5f 55 42 39 35 34 00 00 00 00 00 00 00 00 00 00    _UB954..........


    Dump registers ub954 during video transmission:

         0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 60 00 1e 20 df 01 00 fe 1c 10 7a 7a ad 09 28 7f    `.? ??.???zz??(?
10: 00 00 00 00 00 13 00 00 00 00 00 00 00 00 04 00    .....?........?.
20: 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00    .?..............
30: 00 00 00 01 40 01 00 03 00 00 00 01 14 6f 00 40    ...?@?.?...??o.@
40: 00 a7 71 01 00 00 00 00 00 00 00 12 01 33 ed 64    .?q?.......??3?d
50: 00 00 00 03 00 00 00 00 5e 82 00 30 30 34 00 00    ...?....^?.004..
60: 00 00 00 00 00 34 00 00 00 00 00 00 00 7c 88 02    .....4.......|??
70: 2b 2c e4 04 44 09 60 c5 00 01 0f ff 20 05 00 00    +,??D?`?.??. ?..
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
a0: 02 0f 00 00 08 18 00 00 00 00 00 00 00 00 00 00    ??..??..........
b0: 08 14 3f 08 25 00 18 00 8c 33 83 74 80 00 00 00    ????%.?.?3?t?...
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
d0: 00 43 94 02 60 f2 00 02 00 00 00 08 00 00 00 00    .C??`?.?...?....
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
f0: 5f 55 42 39 35 34 00 00 00 00 00 00 00 00 00 00    _UB954..........


    Dump registers ub954 after interrupting video transmission:

         0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 60 00 1e 20 df 01 00 fe 1c 10 7a 7a ad 09 28 7f    `.? ??.???zz??(?
10: 00 00 00 00 00 13 00 00 00 00 00 00 00 00 04 00    .....?........?.
20: 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00    .?..............
30: 00 00 00 01 40 01 00 00 00 00 00 01 14 6f 00 40    ...?@?.....??o.@
40: 00 a7 71 01 00 00 00 00 00 00 00 12 01 03 0c 64    .?q?.......????d
50: 00 00 00 03 00 00 00 00 5e 82 00 30 30 34 00 00    ...?....^?.004..
60: 00 00 00 00 00 34 00 00 00 00 00 00 00 7c 88 02    .....4.......|??
70: 2b 2c e4 04 44 09 60 c5 00 01 0c ff 20 05 00 00    +,??D?`?.??. ?..
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
a0: 02 0f 00 00 08 18 00 00 00 00 00 00 00 00 00 00    ??..??..........
b0: 08 14 3f 08 25 00 18 00 8c 33 83 74 80 00 00 00    ????%.?.?3?t?...
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
d0: 00 43 94 02 60 f2 00 02 00 00 00 00 00 00 00 00    .C??`?.?........
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
f0: 5f 55 42 39 35 34 00 00 00 00 00 00 00 00 00 00    _UB954..........


    Do I understand correctly that the problem is on the side of ub954 / 953?
    What changes do I need to make to fix the problem?

  • 0 in reply to SVL SVL
    TI__Guru** 103215 points

    SVL,

    From your first message, the MIPI rate for your sensor at 120Hz is 891Mbps/lane which is above the maximum CSI-2 lane speed of the 953. This is why it does not work. With 25MHz REFCLK, the maximum CSI-2 lane speed is 800Mbps/lane at the 953 side, so please reduce the lane speed of the sensor to make sure it meets the requirement. 

    Best Regards,

    Casey 

  • 0 in reply to Casey McCrea
    Prodigy 130 points

    Thanks for your reply.
    Changing the REFCLK to 26MHz will solve the problem?
    891Mbps/lane not possible at 953 at all?
    Maybe you can advise what solution to use instead of 953 to load 891Mbps / lane?
    I found the value of 832Mbps in the datasheet but it is not entirely clear for which REFCLK it is provided.

  • 0 in reply to SVL SVL
    TI__Guru** 103215 points

    Hello SVL,

    The maximum allowable 4 lane CSI-2 speed is REFCLK*32. So for 26MHz REFCLK (maximum supported REFCLK), the max per lane speed is 26*32 = 832MHz. There is no way to get 891 functional since it is outside the operating range of this device. 

    Best Regards,

    Casey 

  • 0 in reply to Casey McCrea
    Prodigy 130 points

    Hello Casey,
    Thanks for your reply.

    Best Regards,

    SVL