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Enhanced Direct Memory Access (eDMA)
19-28
Freescale Semiconductor
Figure 19-31. eDMA Operation, Part 3
19.6
Initialization/Application Information
19.6.1
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 DCHPRI
n
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 TCD
n
_CSR[START] bit) or hardware (slave
device asserting its eDMA peripheral request signal).
2
1
n-1
Transfer
Control
Descriptor (TCD)
eDMA Engine
Data Path
eDMA
eDMA Peripheral
0
Program Model/
Write Address
Write Data
Read Data
Read Data
Write Data
Address
64
eDMA Done
Control
Channel Arbitration
Address Path
Inter
nal
P
e
ri
p
heral
Bus
T
o
/F
ro
m
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Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...