Enhanced Direct Memory Access Controller (eDMA)
21-44
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
Figure 21-27. eDMA Operation, Part 3
21.5
Initialization / Application Information
21.5.1
eDMA Initialization
A typical initialization of the eDMA has the following sequence:
1. Write the EDMA_
x
_MCR if a configuration other than the default is desired.
2. Write the channel priority levels into the EDMA
_x
_CPR
n
registers if a configuration other than
the default is desired.
3. Enable error interrupts in the EDMA
_x
_EEIRL and/or EDMA
_x
_EEIRH registers if desired.
4. Write the 32-byte TCD for each channel that may request service.
5. Enable any hardware service requests via the EDMA
_x
_ERQRH and/or EDMA
_x
_ERQRL
registers.
6. Request channel service by software (setting the EDMA
_x
_TCD.START bit) or by hardware
(slave device asserting its DMA peripheral request signal).
Slave in
terface
eDMA
eDMA done
System bus
Slave write data
Slave write address
Bus write data
Slave read data
Bus address
eDMA engine
TCD0
TCD
n –
1*
eDMA peripheral
Bus read data
request
SRAM
Transfer control descriptor
(TCD)
SRAM
Data path
Address
path
Control
Program model/
channel arbitration
*n = 32 (64 for eDMA_A) channels
Summary of Contents for PXR4030
Page 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Page 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
Page 40: ...PXR40 Microcontroller Reference Manual Rev 1 xl Freescale Semiconductor...
Page 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Page 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
Page 1168: ...Decimation Filter 28 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...