Initialization/Application Information; Edma Initialization - Freescale Semiconductor MCF5329 Reference Manual

Enhanced Direct Memory Access (eDMA)
eDMA
eDMA Engine
Read Data
Data Path
Write Data
Address
16.8

Initialization/Application Information

16.8.1

eDMA Initialization

A typical initialization of the eDMA has the following sequence:
1. Write the EDMA_CR if a configuration other than the default is desired.
2. Write the channel priority levels into the DCHPRIn registers if a configuration other than the
default is desired.
3. Enable error interrupts in the EDMA_EEI if so desired.
4. Write the 32-byte TCD for each channel that may request service.
5. Enable any hardware service requests via the EDMA_ERQ.
6. Request channel service by software (setting the TCDn_CSR[START] bit) or hardware (slave
device asserting its eDMA peripheral request signal).
16-28
Program Model/
Channel Arbitration
Address Path
eDMA Peripheral
Figure 16-31. eDMA Operation, Part 3
MCF5329 Reference Manual, Rev 3
Transfer
Control
Descriptor (TCD)
64
Control
eDMA Done
Request
Freescale Semiconductor
Write Address
Write Data
0
1
2
n-1
Read Data