send pattern data in CyCx3UvcAppDmaCallback

AnWa_3863696 · ‎May 18, 2020

Hi

Is it possible to send pattern frame in UVC application from CX3 module FW in every DMA callback?

I try to modify dmaBuffer.buffer content, but the result seems only around 60 bytes data were modified that captured by USB wireshark.

What's wrong with my code or any limitation for change frame buffer?

status = CyU3PDmaMultiChannelGetBuffer(chHandle, &dmaBuffer, CYU3P_WAIT_FOREVER);

while (status == CY_U3P_SUCCESS)

{

/* Add Headers*/

if(dmaBuffer.count < CX3_UVC_DATA_BUF_SIZE)

{

#ifdef UVC_APPLICATION

CyCx3UvcAppAddHeader ((dmaBuffer.buffer - CX3_UVC_PROD_HEADER), CX3_UVC_HEADER_EOF);

CyU3PMemCopy(dmaBuffer.buffer+CX3_UVC_PROD_HEADER, ptrEEPROM, 0x4000);

#endif

Thanks

Angus

Hemanth · ‎May 18, 2020

Hi Angus,

Angus Wang wrote:
I want to replace the entire video frame with local buffer data. Is this possible?

>> Please refer to following example in the FX3 SDK:

C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\firmware\uvc_examples\cyfxuvcinmem_bulk

(Please check readme file of the project)

You have to use CY_U3P_DMA_TYPE_MANUAL_OUT channel instead of CY_U3P_DMA_TYPE_MANUAL_MANY_TO_ONE

Note: I assume that you don't want to use MIPI interface at all.

Regards,

Hemanth

Re: send pattern data in CyCx3UvcAppDmaCallback