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USB Low-Full-High Speed Peripherals

Anonymous
Not applicable

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 = *(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

   

 

   

{

myDev.ControlEndPt.ReqType =

myDev.ControlEndPt.Direction =

myDev.ControlEndPt.ReqCode = (

myDev.ControlEndPt.Value = (

myDev.ControlEndPt.Index = (

 

 

 

 

    if    (myDev.ControlEndPt !=     null    )    CyConst    .REQ_VENDOR;    CyConst    .DIR_FROM_DEVICE;    byte    )    Commands    .VR_XSVF_COMMAND;    ushort    )cmd.Length;    ushort    )0;    int    len = cmd.Length;    if    (myDev.ControlEndPt.XferData(    ref    cmd,     ref    len))    return    (    XSVFErrorCodes    )cmd[0];    else   

 

}

}

 

    return        XSVFErrorCodes    .XSVF_USB_COMMAND_FAILED;    return        XSVFErrorCodes    .XSVF_NO_DEVICE;
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1 Reply
Anonymous
Not applicable

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

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