Received Data length is wrong in usb Communication

[Sarathk3k]

"static uint8_t USBD_CDC_DataOut(USBD_HandleTypeDef *pdev, uint8_t epnum)"

In stm32u575 controller and in this function while I am calling

"uint32_t receivedLength = USBD_LL_GetRxDataSize(pdev, epnum);" it gives me 1 insted of 6 or 5 bytes I am reciving so that I could not get entire data

 

[TDK]

Probably the data is being split up into several packets. What program is sending the data?

[Sarathk3k]

It is a company software.We have to communicate with that.

void HAL_PCD_IRQHandler(PCD_HandleTypeDef *hpcd)

In this function ep->xfer_count += (RegVal & USB_OTG_GRXSTSP_BCNT) >> 4;  the xfer_count becomes 1 instead of 6 bytes or 5 bytes we are receiving. If I forcefully put it into 6 .I will get the first entire string.