DMA processor

The DMA (Direct Memory Access) controller, is often a non-programmable hardware. As new peripheral interfaces are introduced there is often a need to change the DMA operation and therefore the design of the DMA controller. Changing the design of the DMA controller is often expensive and time-consuming. Instead, a fully programmable DMA processor can alter the behaviour by simply changing a control program. This paper describes an approach for a programmable DMA processor for a future ETRAX processor developed by Axis Communications. To reach the design solution, different instruction set architectures were simulated and investigated. The result is a fully programmable DMA processor with one RISC core and several burst controllers that handles the data transfers. It can transfer data in parallel with up to 16 channels. The DMA processor is able to work with 1 Gbit/s full duplex Ethernet when the DMA processor is running at 100 MHz. The program that controls the DMA operations is stored in a local instruction memory of the DMA processor. When synthesized with 0.25 um technology, the DMA controller has a 160 000 gate foot print without the instruction memory.Validerat; 20101217 (root