DS90UB638-Q1: [DS90UB638TRGZRQ1] After setting FPD-Link III Parity Checker Enable, the image is stuck.

Hello,

Thank you for reaching out. Can you explain exactly what you are setting here? The parity checker is enabled by default and should not need to be set.

Hello,

We set this register to 0x30 when deserializer initialized.

Recently we were doing an ESD experiment and the screen flickered,

so we wanted to turn on this detection function to see if there was any decoding error.

But after we enable this bit, the screen will freeze. After disabling this bit, the screen will resume display.

Best Regards,

Songqing Lin

This likely means that the ESD event is resulting errors on the channel. The parity errors in particular, when being detected by the device, may be resulting in a loss of lock. With loss of lock the video stream to the display is interrupted, which the display may be responding to by freezing on the last received frame (this would be a display specific feature/setting).

Before starting ESD test, we enable this bit, the screen will freeze. After disabling this bit, the screen will resume display.

So I think this has nothing to do with the screen.

Are you using EVMs or custom boards? What partner device is being used with the 638? What do you mean by the screen freezing? Are frames no longer being output by the deserializer, is the display stuck on the last frame, does the screen go black? Are there any error checking or diagnostics being done on the output image or screen? Is a camera/imager being used to generate the image on the screen, if so does the pattern generator of both the serializer and deserializer see the same behavior? Please provide a register dump of the deserializer before and after the issue occurs.

We are using custom boards. OX03C10 sensor + ds90ub953 is used with 638. 

The image display on the monitor is freeze when we enable this bit.  

Deserializer has no frame output

Yes, the display is stuck on the last frame.

We will test again then dump the register and send it to you later.

Please note that the DS90UB953 and DS90UB638 are not compatible devices. The DS90UB638 is only compatible with other DS90UB6xx devices, such as the DS90UB635. For compatibility details, you can reference the "Features" or "Overview" section of a respective device's data sheet. For non-testing production units/systems, it is recommended to update either the serializer and deserializer so the pair is compatible.

If the deserializer has no output, then the display is not receiving data. This is resulting in the display freezing on the last received frame until additional frames are received. As mentioned previously, this can be caused by a loss of lock from parity errors. The diagnostic registers can confirm if parity or other errors are occurring.