USB ISP 1760 1761 Misunderstood

Hi all,

I wonder if it is interresting to implement the DMA transfert on the isp1760/1761. Indeed, I do not understand what it can bring.

After having a look to the driver and have make some test, the DMA transfert protocol will just releive the CPU (NIOS II) during the transfer of PTD from RAM to ISP.

However this time is very short compare to the time of creating a PTD in RAM.

The aim of the project was to increase the transfer rate over a USB memory Stick plug to an ISP. The file system is Ext2, NIOS II running uClinux @ 125MHz with a DDR2-333 16bit@167MH.

Actually I am between 3 and 3.5 Mbyte/s (24 and 28 Mb/s)

Thank you