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USB Superspeed Peripherals

bayi_4531756
New Contributor

I create a project with CX3 configuration tool. The sensor is a time of flight sensor.And I configure the right parameter. After running, I cannot get frame data. I measure the LV(HSync) and FV(VSync) signals and find that they are not generated. But I measure the mipi data lane and find that there is data and signal on all the data lane. The signal on the clock lane is right,but the level on one clock line is twice the level on the other clock line.For examaple, the level on one clock line is 600 mV,then the level on the other clock line is 280 mV. This should not be right. So what is the problem?

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1 Solution
Rashi_Vatsa
Moderator
Moderator

Hello,

Please let me know what is FPC.

- In the MIPI configuration, you have mentioned the CSI Clock to be 270 MHz. Why it is 270 MHz. The clock (waveform) in you previous post shows that clock frequency is 135 MHz

You said the the clock from sensor is 45 MHz. Please confirm.

- The CSI clock field in the tool should be populated with clock frequency which is provided by the Camera sensor (MIPI Transmitter).

-All the fields on the left hand side of the tool i.e under MIPI CSI2 Inputs should be populated with values coming from the Camera sensor.

-The right hand side i.e. CX3 MIPI Interface  Configuration can be tweaked to get the pixel clock which would be used for CX3

- Jumpers can be the cause of problem as the clock frequency is too high. You cannot use jumper for these lines. We would recommend to have proper routing of the MIPI lines.

Regards,

Rashi

Regards,
Rashi

View solution in original post

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13 Replies
Rashi_Vatsa
Moderator
Moderator

Hello,

Can you share the CX3 configuration tool snapshot.

Also, share the traces after probing the MIPI lines .

Regards,

Rashi

Regards,
Rashi
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bayi_4531756
New Contributor

hi, below is the snapshot of my configuration file. As for the traces after probing the mipi lines, do you means the usb bus trace log or snapshot of

signal waveform of Oscilloscope?CX3.PNG

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Rashi_Vatsa
Moderator
Moderator

Hello,

Yes, i would need the signal waveform of the MIPI data lines

Regards,

Rashi

Regards,
Rashi
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bayi_4531756
New Contributor

Rash, the first figure is the signal waveform of clock lane, and the others are the signal waveform of data lane. Could you tell why one clock line has a higher bias level?

TEK0001.BMP

TEK0004.BMP

TEK0005.BMP

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bayi_4531756
New Contributor

Hi, RashiV:

       Could you give any clues after studying the waveform figures of mipi lines?

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Rashi_Vatsa
Moderator
Moderator

Hello,

It doesn't seem that two clock level is problem caused due to CX3 (as this is coming from the camera sensor)

This abnormality in the clock signals from the MIPI transmitter can be a reason for not getting HSYNC, VSYNC.

We need to check the MIPI transmitter (camera). Please check the Camera settings.

I am working on it too. Will let you know if i find something on it.

Regards,

Rashi

Regards,
Rashi
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bayi_4531756
New Contributor

Rashi, could you make sure or answer the following several qustions?

1.  The following figure is my final  product configuration. The pixel clock of image sensor is 45Mhz. For image sensor dummy pixel number between lines is 62 and dummy lines number between frames is 27. Image Sensor occupies two mipi data lanes and uses RAW12 data format. Could you make sure whether the parameter configuration is right in the figure?

2. Our formal image sensor has not come into being. So I use a similar product(image sensor).The substitute works fine on Raspberry. And when it works on Raspberry, the level of two clock line is close and there is not high level bias. Do you know where the problem could be located?

3. As mentioned in 2, the substitute uses FPC connection for mipi output. This connection is not compatible with the CX3 interface. So I use flying wire connection to draw out and connect the line in FPC to corresponding pin in CX3 interface. Could this connection lead to the higher clock level bias problem?

            Thank you.

正式.PNG

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Rashi_Vatsa
Moderator
Moderator

Hello,

Please let me know what is FPC.

- In the MIPI configuration, you have mentioned the CSI Clock to be 270 MHz. Why it is 270 MHz. The clock (waveform) in you previous post shows that clock frequency is 135 MHz

You said the the clock from sensor is 45 MHz. Please confirm.

- The CSI clock field in the tool should be populated with clock frequency which is provided by the Camera sensor (MIPI Transmitter).

-All the fields on the left hand side of the tool i.e under MIPI CSI2 Inputs should be populated with values coming from the Camera sensor.

-The right hand side i.e. CX3 MIPI Interface  Configuration can be tweaked to get the pixel clock which would be used for CX3

- Jumpers can be the cause of problem as the clock frequency is too high. You cannot use jumper for these lines. We would recommend to have proper routing of the MIPI lines.

Regards,

Rashi

Regards,
Rashi

View solution in original post

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bayi_4531756
New Contributor

Hi, Rashi:

     I have another question. My substitute image sensor's mipi clock mode is continuous mode.It works fine on Raspberry and on Raspberry the XRST and XSHUTDOWN pin of image sensor is not connected. So when I connect the image sensor to the CX3 interface via jumpers, the XRST and XSHUTDOWN pins are not connected too. Could the disconnection lead to any problem?

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Rashi_Vatsa
Moderator
Moderator

Hello,

You can refer to this Q 13 of this KBA CX3 Hardware: Frequently Asked Questions - KBA91295

As i had mentioned in my previous response that jumpers for MIPI lines are not recommended. MIPI lines are high frequency lines so using jumpers wouldn't be good.

We recommend to connect XRST pins which will help in resetting the sensor as mentioned in Q 13 of KBA

- Upon receiving the Set_Cur (Commit control) request from the host, perform a MIPI reset (CyU3PMipicsiReset() with the reset type as Hard reset ).

Also, the XRST will keep the sensor in reset mode until the CX3 MIPI is initialized.

Regards,

Rashi

Regards,
Rashi
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bayi_4531756
New Contributor

hi,Rashi:

      I use the function(CyU3PMipicsiSetSensorControl) to set XRST pin(F4) in esUVCUvcApplnInit(), and I measure the level of XRST pin, it is 0. It seems that my configuration does not take effect. The value in register 0x0014 is 0x2(refer to the figure below), it means driving XRST high. So what is thReset.PNGe problem?

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bayi_4531756
New Contributor

hi,Rashi:

         After hard work, now I can get the HSync and VSync test signals. And I can also get the frame data. But there is a problem. The frame data is not stable and there is always data flicker. I have use the API CyU3PMipicsiSetPhyTimeDelay to set the physical value and I also adjust the value. But the adjustment does not work. There is always data flicker or glitch. So which parameter should I adjust?

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Rashi_Vatsa
Moderator
Moderator

Hello,

Can you share the traces of HSYNC and VSYNC?

Please let me know how are you checking for the glitches?

Regards,

Rashi

Regards,
Rashi
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