Some info: DMAC allows you transfer data to/from memory (RAM) or peripheral devices in a shortst possible time, it eliminates the access time of the control ROMs. DMA takes control of all tha buses over the MPU to access memory and allows you transfer large amounts of data.
hi,
how are the dreq(dma request) related to the channels in the dma controller.
In some spec it is shown that there are four channels and there are 4-bit dreq signals. The spec i referred was :
**broken link removed**
Further more can anyone give me a simple design of a dma controller.
You should read some related document, especially in microarchitecture.The theory and background is important. basically DMA want to release the overload from CPU, so you must know the architecture of your target system including the cpu,bus system,etc.