Overview - Freescale Semiconductor MCF52277 Reference Manual

Chapter 17
Enhanced Direct Memory Access (eDMA)
17.1

Overview

The enhanced direct memory access (eDMA) controller is a second-generation module capable of
performing complex data transfers with minimal intervention from a host processor. The hardware
microarchitecture includes a DMA engine that performs source- and destination-address calculations, and
the actual data-movement operations, along with local memory containing transfer control descriptors for
each channel.
17.2 Block Diagram
Figure 17-1 is a block diagram of the eDMA module.
eDMA
eDMA Engine
Read Data
Write Data
Address
Freescale Semiconductor
Data Path
Figure 17-1. eDMA Block Diagram
MCF52277 Reference Manual, Rev. 1
Transfer Control
Descriptor (TCD)
64
Program Model/
Channel Arbitration
Address Path
Control
eDMA Peripheral
Request
Write Address
Write Data
0
1
2
15
Read Data
eDMA Done
17-1