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USB superspeed peripherals

SLLe_1656711
New Contributor

Hi,

I've a problem that the output frame rate of cx3 usb only half of the input.

The sensor's VS is 30Hz.

The VSYNC_TEST in cx3 is 30Hz.

I can get correct image frames from USB but the frame rate is only 15Hz.

I measure a gpio that toggle in the callback function of GPIF while get the event "CYU3P_GPIF_EVT_SM_INTERRUPT".

The frequence is 7.5Hz. That means the frequence of this event is 15Hz.

What is the cause of this problem?

Regards,

Lee

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1 Solution
SLLe_1656711
New Contributor

Hi Hemanth,

Thanks for your reply.

This problem has been solved after extend the pulse width of VSYNC in sensor around to 250us.

Is there any requirement about the pulse width of VSYNC for CX3?

Regards,

Lee

View solution in original post

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3 Replies
Hemanth
Moderator
Moderator

Hi Lee,

- What is your video resolution and pixel bit depth?

- What are the parameters that you passed when calling CyU3PMipicsiGpifLoad()

- What is the active time and blanking time of VSYNC_TEST?

Regards,

Hemanth

Hemanth
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SLLe_1656711
New Contributor

Hi Hemanth,

Thanks for your reply.

This problem has been solved after extend the pulse width of VSYNC in sensor around to 250us.

Is there any requirement about the pulse width of VSYNC for CX3?

Regards,

Lee

View solution in original post

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Keerthy
Moderator
Moderator

Hello Lee,

If you are using the latest CX3 state machine available with SDK 1.3.4, then the minimum vertical blanking required is around 200uS.

If you are using the state machine available with SDK 1.3.3, then the minimum vertical blanking needed is around 500uS.

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