Overview

Channel 0 Channel 1 Channel 2 Channel 3

Internal

SAR0

SAR1

 

SAR2

SAR3

 

Bus

DAR0

DAR1

 

DAR2

DAR3

Interrupts

 

 

External

BCR0

BCR1

 

BCR2

BCR3

 

Requests

DCR0

DCR1

 

DCR2

DCR3

 

 

 

 

 

DSR0

DSR1

 

DSR2

DSR3

 

Channel

 

 

Channel

 

 

Requests

 

 

Attributes

 

 

 

Channel

 

System Bus Address

 

 

Enables

MUX

 

 

 

 

System Bus Size

 

 

 

MUX

 

Current Master Attributes

 

 

Control

 

 

 

 

 

 

Arbitration/

 

 

 

 

Control

 

 

 

 

Data Path

 

 

 

 

Bus Interface

 

 

Data Path

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Control

 

 

 

 

Registered

 

 

 

 

 

 

 

 

 

Read Data Bus

 

 

Write Data Bus

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bus Signals

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 16-1. DMA Signal Diagram

NOTE

Throughout this chapter “external request” and DREQ are used to refer to a DMA request from one of the on-chip UARTS or DMA timers. For details on the connections associated with DMA request inputs, see Section 16.2, “DMA Request Control (DMAREQC).”

16.1.1 DMA Module Features

The DMA controller module features are as follows:

Four independently programmable DMA controller channels

Auto-alignment feature for source or destination accesses

Dual-address transfers

Channel arbitration on transfer boundaries

Data transfers in 8-, 16-, 32-, or 128-bit blocks using a 16-byte buffer

Continuous-mode or cycle-steal transfers

Independent transfer widths for source and destination

Independent source and destination address registers

16-2

MCF5282 User’s Manual

MOTOROLA

Page 342
Image 342
Motorola MCF5282, MCF5281 user manual DMA Module Features, Channel 0 Channel 1 Channel 2 Channel