fpga4fun.com

Hi,

I am not much into programming hence this question.In the office I have been handed over this Dragon PCI FPGA Board. I am able to write to the FPGA using the simple codes provided by you ( as indicated by LEDs). But I am unable to read what I have written into it.

As I am trying to find out why I cannot read back the one byte of data I have written into it I am quite baffled as to why you need USB_BulkWrite inside USB_BulkRead as in

void USB_Read(void* buffer, WORD buffersize)
{
if(buffersize==0) return;
USB_BulkWrite(6, &buffersize, 2);
USB_BulkRead(3, buffer, buffersize);
}

like in the initial USB_BulkWrite the value is 2. what is this pipe value which is changing from 2to 6 to 3. Commenting that portion makes the simple C console program get stuck.

I would like help in reading back what I have written into it+ the explanation of code.

thnx in advance
Neetu

What did you program in the FPGA?
You have to look at the code you programmed into the FPGA to see what value it would return on a read.

Also the write before a read is there to indicate to the USB controller how many bytes you are going to read. Make sure to read the board doc, chapter 4 and forward, and study the board USB tutorials.

I burned the USB IO8 program available with the Dragon Start up Kit.
Is this the right way to read back the data
void main()
{
BYTE b[1*8];
void USB_Open();
USB_WriteByte(07);
USB_Read(b,sizeof(b));
printf("%b", b);
void USB_Close();
exit(0);
}


thnx
Neetu