Hello
I am having problems with the NIOS system and the DMA controller that I am using and was hoping someone might be able to tell me what I'm doing wrong.
It is a simple set up, I transfer 26 bytes from onchip memory to onchip memory (or my real application which is a USB controller).
The program I have at the moment just loops continuously transferring data from one to the other and works well except for the first block of data. The first data byte is repeated a number of times.
When I look at the system using SignalTap it looks as if the initial read is being delayed a couple of clock cycles and at least the first two read locations are incorrectly returning the same data instead of the incrementing values I know are stored there. This was tested by individually reading each location.
Any ideas? Do I have to do anything other than setting the control register and clearing the done signal? Could it be a problem with the FIFO in the DMA? I have set the DMA to byte transfer only.
thanks
