I have an application based on the Vend_ax sample.  I have one command that will not send a response back.  I load EP0, but it is never sent.

If I comment out #1 and #2, then I get a response back, but I do not get my two bytes of data after the control "header".

case VR_XSVF_COMMAND:
#if  1  //jad ENABLE_FPGA_PROGRAMMING
   EP0BCH = 0;                                                                                              //<<<<<#1
   EP0BCL = 0; // Clear bytecount to allow new data in; also stops NAKing         //<<<<<#2

   while(EP0CS & bmEPBUSY);

   blockLen = EP0BCL;
   for(i=0; i<blockLen; i++)
   {
    fileStorage[i] = *(EP0BUF+i);
   }
#if 0 //jad        
   if (xsvfFirstCommand == 1)
   {
    xsvfFirstCommand = 0;
    xsvfInitialize();
   }

   *EP0BUF = xsvfRun();
#endif
//jad*EP0BUF = 0xFF;
#else
   *EP0BUF = 0xFF;
#endif // ENABLE_FPGA_PROGRAMMING
   EP0BCH = 0;
   EP0BCL = 1;   // Arm endpoint with # bytes to transfer
   EP0CS |= bmHSNAK; // Acknowledge handshake phase of device request
   break;

The PC code is  (cmd[] = 0x07 0x00) :

if

(myDev != null)

{

//jad implement sending to board

Hi dreitz,

This is expected as you are assigning the EP0BCL register at the begining of the vendor command ,

EP0BCH = 0;                                                                                              //<<<<<#1
   EP0BCL = 0; // Clear bytecount to allow new data in; also stops NAKing         //<<<<<#2

This will commit the EP0 buffer with 0 bytes and you would not receive any data.You should first initialize the buffer and then write to these registers as you are doing at the end in your code.

-shub