fpga(DMA CONFIGURATION)

[ekanth]

HI

Iam pumping in serial data(RS 422) AT BAUD RATES OF (4800bps to 38400 bps) at different channels.Iam using flex rio (7965 R) WITH FLEX RIO adapter (NI 6584).I wanted to know what should be configuration  of dma(target to host) which is requested number of elements and the data type(fpga side)

And also what does requested number of elements means? is it bytes or kilobytes?

Regards

EKANTH

[GregFreeman · Accepted solution]

Requested number of elements is neither bytes nor kilobytes. It is the number of elements and the number of bytes will be based on the datatype you choose. So, if your dma holds I32s and you choose 8 elements, it will be 32 bytes. Knowing that, you should be able to figure out how many elements you need. It also depends on the RT controller you have. The faster you can dequeue elements from the FIFO, the fewer number of elements it needs to hold.