AnsweredAssumed Answered

MIPI Clock questions

Question asked by Titus Stalin on Mar 30, 2017
Latest reply on Apr 11, 2017 by Titus Stalin

Hello,

 

Took the below details from page no 2725, Reference manual:

 

The maximum bandwidth of the interface is as follows:
• 200Mhz for 4 data lanes configuration (800Mbps/lane, 400MByte/sec)
• 187.5Mhz for 3 data lanes configuration (1000Mbps/lane, 375MByte/sec)
• 125Mhz for 2 data lanes configuration (1000Mbps/lane, 250MByte/sec )
• 62.5Mhz for 1 data lane configuration (1000Mbps/lane, 125Mbyte/sec)

 

Can you please answer the following questions ?

What is all about the 200MHz, 187.5MHz, 125MHz and 62.5MHz clock values ?

Where we can see/get the clock ?

Is it differential lane clock ?

Then what is the clock for OV5640 MIPI camera ?

 

I've the customized MIPI camera which supports 4 lanes, how can I get the clock range ?

Need to measure the CLK_P and CLK_N pins ?

What is the sensor clock and MIPI lane clock ?

 

I've got the below details from below imx link.

Debug steps for customer MIPI sensor.docx 

 

 

  1. MIPI DPHY clock should match the camera sensor clock, as the sensor  output Differential clock  range is from 80Mhz to 1000Mhz .

Example:

-     mipi_csi2_write(info, 0x00000014, CSI2_PHY_TST_CTRL1);//ov5640 output clk

+    mipi_csi2_write(info, 0x00000044, CSI2_PHY_TST_CTRL1);//Customer camera sensor

 

Tips:

 

The range and the exact value when ref_clock is 27M are showed as below:

#define                PLL_CLK  0x32  //783Mhz

                           // clock_range : register value // exact value when ref clock is 27M

                           //  950-1000MHz :0x74   //999Mhz

                           //  900-950Mhz  :0x54   //972Mhz

                           //  850-900Mhz  :0x34   //900Mhz

                           //  800-850MHz  :0x14   //849Mhz

                           //  750-800MHz  :0x32   //783Mhz

                           //  700-750Mhz  :0x12   //750Mzh

                           //  650-700Mhz  :0x30   //699Mhz

                           //  600-650MHz  :0x10   //648Mhz

                           //  550-600MHz  :0x2e   //600Mhz

                           //  500-550Mhz  :0x0e   //549Mhz

                           //  450-500Mhz  :0x2c   //486Mhz

                           //  400-450MHz  :0x0c   //450Mhz

                           //  360-400MHz  :0x4a   //399Mhz

                           //  330-360Mhz  :0x2a   //360Mhz

                           //  300-330Mhz  :0x48   //330Mhz

                           //  270-300MHz  :0x28   //300Mhz

                           //  250-270MHz  :0x08   //270Mhz

                           //  240-250Mhz  :0x46   //249Mhz

                           //  210-240Mhz  :0x26   //240Mhz

                           //  200-210MHz  :0x06   //210Mhz

                           //  180-200MHz  :0x44   //198Mhz

                           //  160-180Mhz  :0x24   //180Mhz

                           //  150-160MHz  :0x04   //159Mhz

                           //  140-150MHz  :0x42   //150Mhz

                          //  125-140MHz  :0x22   //135Mhz

                          //  110-125MHz  :0x02   //123Mhz

                          //  100-110Mhz  :0x40   //108Mhz

                          //  90-100Mhz   :0x20   //99Mhz

                         //  80-90Mhz    :0x00   //90Mhz (default)

 

 

What is the reference clock here 27MHz ?

Is it used inside the imx or camera sensor ?

How its derived and its same all the time ?

 

Thanks for answering the questions.

 

Regards,

Titus S.

Outcomes