usb transfer between PC and de2 board

"summer5" skrev i meddelelsen news:e7adnYqLapvxZP3WnZ2dnUVZ snipped-for-privacy@giganews.com...

A USB bus analyzer.

Leo Havmøller.

Hi,

Thanks for the reply. :>

i had change the coding.

This is the coding from HAL4D13.c USHORT Hal4D13_ReadEndpoint(UCHAR bEPIndex, UCHAR *buf, USHORT len) { USHORT i, j, c; IOWR(ISP1362_BASE,D13_COMMAND_PORT, D13CMD_EP_RD_FIFO + bEPIndex); /* read Buffer */ j = IORD(ISP1362_BASE,D13_DATA_PORT); if(j > len) j = len; i=0; while (i8); i++; buf++; } /* Clear Buffer */ IOWR(ISP1362_BASE,D13_COMMAND_PORT, D13CMD_EP_CLEAR_BUF+bEPIndex); return j;

Do anyone knows the meaning of *buf = (UCHAR)(c>>8)? Especially the(c>>8) in the coding. Is it is shift to right for 8 bytes?

Thanks, Summer

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With the assumption that USHORT == 16bit and UCHAR == 8bit, the code in the inner loop first copies the lower 8 bits from the 16 bit word in c to the location pointed to by buf and then copies the higher 8 bits from the 16 bit word to the next location ion the buffer.

(c>>8) shifts the higher 8 bits in the 16 bit word to the lower 8 bits.

Without knowing much about USB communication, it seems to me that if the requested len is less than available (j) you loose the difference because you only copy len characters at most and then declare the transaction complete!

Antoon

Hi,

may i know is the USB bus analyzer is in software form like hardware in SOPC of Quartus II or we need buy a real exist hardware?

Thanks, Summer

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hi, if i use the software only USB analyzer, can i able to check what is going wrong in my DE2-side code? As i check from internet and it says software only USB analyzer only useful for checking PC-side code.

thanks, summer

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