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Enhanced Direct Memory Access (eDMA)
Freescale Semiconductor
19-27
Figure 19-30. eDMA Operation, Part 2
After the minor byte count has moved, the final phase of the basic data flow performs. In this segment, the
address path logic performs the required updates to certain fields in the appropriate TCD, e.g., SADDR,
DADDR, CITER. If the major iteration count is exhausted, additional operations are performed. These
include the final address adjustments and reloading of the BITER field into the CITER. Assertion of an
optional interrupt request also occurs at this time, as does a possible fetch of a new TCD from memory
using the scatter/gather address pointer included in the descriptor. The updates to the TCD memory and
the assertion of an interrupt request are shown in
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
Crossbar
Switch
Request
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 ...