topic Re: Is it possible to achieve TRM mentioned data rate in MIPI CSI ? in i.MX Processors

Is it possible to achieve TRM mentioned data rate in MIPI CSI ?

titusstalin — Thu, 26 Oct 2017 10:41:17 GMT

Hello,

I have interfaced our 4 lane supported camera into i.MX6 board and written our own camera driver based on i.MX6 reference camera OV5640 driver.

TRM mentioned that MIPI CSI2 supports data rate upto 800Mbps per lane when we use 4 lane configuration and 1Gbps/lane when we use 1/2/3 lane count.

IMX6DQRM.pdf, page no 450.

One MIPI/CSI-2 port- IPU receives two components per cycle from the MIPI_CSI2
interface. The maximum bandwidth of the interface is as follows:
• 400MByte/sec for four data lanes configuration (800Mbps/lane)
• 375MByte/sec for 3 data lanes configuration (1000Mbps/lane)
• 250MByte/sec for 2 data lanes configuration (1000Mbps/lane)
• 125Mbyte/sec for 1 data lanes configuration (1000Mbps/lane)

I can achieve 1Gbps/lane for 1/2/3 lane configurations as mentioned in TRM but unable to achieve 800Mbps/lane for 4 lane configuration, we are able to get 790Mbps/lane.

If we increase the CSI camera clock from 395MHz to 400MHz to support 800Mbps/lane, we are getting distorted frames.

So we wanted to know that really we can achieve the mentioned data rate for 4 lanes or its just based on theoritical calculation.

Thanks for your support.

Re: Is it possible to achieve TRM mentioned data rate in MIPI CSI ?

igorpadykov — Thu, 26 Oct 2017 23:13:24 GMT

Hi Titus

reason may be ipu bandwidth issue, please try with baremetal sdk (or remove other drivers/applications

from test).

Github SDK
https://github.com/backenklee/swp-report/tree/master/iMX6_Platform_SDK

Right, mentioned data rate is based on theoritical calculation.

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

Re: Is it possible to achieve TRM mentioned data rate in MIPI CSI ?

titusstalin — Fri, 27 Oct 2017 12:48:29 GMT

Thanks Igor.

Actually I can't use this SDK since its very old and our nitrogen specific board support code will not be available.

And also could you please check the data rate with your customers who using 4 lanes for their camera ?

Any other method to verify this ?

Thanks for your help!

Re: Is it possible to achieve TRM mentioned data rate in MIPI CSI ?

eason-tang — Fri, 21 Aug 2020 06:50:13 GMT

Hi titusstalin‌ :

Did you have find out how to achieve the mentioned data rate of 800Mbps with 4-lanes?

I found mipi-csi2-rx maybe could not support up to 800Mbps with 4-lanes.

Best Regard.