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Weird phenomenon in RT1052 while transmit massive data through usb

Question asked by Eric Chen on Jun 30, 2020
Latest reply on Jul 15, 2020 by Victor Jimenez

Hi all

 

I'm facing a weird problem when using usb_vcom_bm on rt1052.

Example as below (modify from official usb_vcom_bm sdk example)

It should transmit over 30000 bytes at once from rt1052 to pc after receiving a command code.

 

int main(void)

{

   InitBoard();

   InitUSB();

   while(1)

   {

      AppUsb(); //Receive command

      AppUsbTransmit();  //Transmit massive data after received command flag

   }

}

 

 

However , it seems not stable after this usb device enumerated.

We got a terrible throughput at beginning, after few seconds , throughput raised and never decrease.

Only when this device is re-plug into pc (Re-enumerated) happens.

I did use usb protocol analyzer to check the transmission, nothing weird.

Any suggestions ?  

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