a.3 DMA (Direct Memory Access)

The DMA (Direct memory Access) is a hardware CPU peripheral which enables data transfer from one memory location to another memory location with out the involvement of the CPU. The DMA data transfer requires 0% CPU.

During the DMA cycles the CPU can perform any required computational task. Upon completion of the DMA transfer the DMA can invoke an interrupt.

The DMA can also transfer data between any peripheral and memory. The DMA HW requires the data source address and data a destination address and the number of required bytes to be transferred.

It is possible to generate a linked list of DMA transfers (it is also called chained DMA).

The C6x has a numerous number of DMA's which can manipulate data between the various peripherals and memory devices [1,2].

DMA Bibliography

[1] TMS320C6000 DSP Enhanced Direct Memory Access (EDMA) Controller Reference Guide , http://focus.ti.com/lit/ug/spru234c/spru234c.pdf

[2] C6000 DSP Teaching ROM , http://focus.ti.com/general/docs/university/univ.tsp?templateId=5807&navigationId=10568&path=templatedata/cm/univgen/data/univ_course_rom#c6000 , Chapter 5.