3 Replies Latest reply on Nov 16, 2018 1:26 AM by keaj

    CX3 interfacing to Aptina MIPI imagers (AR0835)

    rdawson_3458186

      Hi, I am looking to interface some of the Aptina MIPI imagers to the CX3.  Has anyone interfaced to the AR0835 8Mpixel imager?  I am having trouble setting up the timing GUI to get the imager to send information to the CX3.  Does anyone have sample code that allows for setting the AR0835 registers?  Thanks in advance for your help.

        • 1. Re: CX3 interfacing to Aptina MIPI imagers (AR0835)
          keaj

          Hi,

           

          1) Can you please let us know the resolution, frame rate and the format of the video data that you are trying to stream?

          2) Probe the MIPI data & clock lanes. Ensure that they are toggling as expected.

          3) Is the MIPI clock gated or continuous? If the sensor is streaming in continuous clock mode, follow the steps mentioned in question

          13 of the following link:

          http://www.cypress.com/knowledge-base-article/cx3-hardware-frequently-asked-questions-kba91295

          4) Print the MIPI CSI error counts over UART by using the API “CyU3PMipicsiGetErrors”. Check if any of the error count is non-zero.

          If yes, double check the sensor configuration.

          5) Vary the ‘thsSettleDelay’ parameter of “CyU3PMipicsiSetPhyTimeDelay()” API to check if the sensor is streaming for any of the delay value. Keep the first parameter as 0x01 always.

          6) If you were able to get zero MIPI errors and if the video is still not streaming probe the following test points

              CX3 pin#

                          Test Signal Name

          H8

                            PCLK test signal

          G6

                            HSYNC test signal

          H5

                            VSYNC test signal

          If only H8 toggles but not the other pins then MIPI CSI configuration may not be correct. Enter the correct values of MIPI CSI image sensor outputs in the tool and configure the PLL dividers appropriately so that the tool will not generate any errors. Make sure to use the latest CX3 configuration tool plugins.

          7) Ensure that all the unused MIPI data lanes are grounded.

          8) If none of the above are working, please share the screenshot of your MIPI CSI configuration tool. Make sure that the values entered in the tool are correct.

          • 2. Re: CX3 interfacing to Aptina MIPI imagers (AR0835)
            rdawson_3458186

            Keaj,

            Thank you for you input! Very helpful.  We were not able to get the error counts down and start receiving packets consistently.  We adjusted the sensor configuration a number of different ways, but still could not get packets transmitting consistently.  We noticed in the CX3 datasheet that it does not recommend using the clock from the CX3 part as an input clock to the pll on the imager.  We think we need a separate, high quality clock next to the imager so the pll can lock.  Do you have insight into why Cypress does not recommend using the CX3 clock as an input to the input clock to the imager?  Does it have too much jitter?

            • 3. Re: CX3 interfacing to Aptina MIPI imagers (AR0835)
              keaj

              Hi,

               

              Yes, it has high jitter which may cause issue video streaming issues. That is the reason why Cypress do not recommend to use MCLK as input clock source for the image sensor.

               

              Regards,

              Keerthy