LM3S1621 Datasheet, PDF (347/947 Pages) Texas Instruments – ARM and Thumb are registered trademarks and Cortex is a trademark

Figure 8-3. Memory Scatter-Gather, Setup and Configuration
1
Source and Destination
Buffer in Memory
2
Task List in Memory
4 WORDS (SRC A)
A
16 WORDS (SRC B)
B
1 WORD (SRC C)
C
4 (DEST A)
16 (DEST B)
1 (DEST C)
SRC
DST
ITEMS=4
Unused
SRC
DST
ITEMS=16
Unused
SRC
DST
ITEMS=1
Unused
“TASK” A
“TASK” B
“TASK” C
Stellaris^® LM3S1621 Microcontroller
3
Channel Control
Table in Memory
SRC
DST
ITEMS=12
Channel Primary
Control Structure
SRC
DST
ITEMS=n
Channel Alternate
Control Structure
NOTES:
1. Application has a need to copy data items from three separate locations in memory into one combined buffer.
2. Application sets up µDMA “task list” in memory, which contains the pointers and control configuration for three
µDMA copy “tasks.”
3. Application sets up the channel primary control structure to copy each task configuration, one at a time, to the
alternate control structure, where it is executed by the µDMA controller.
4. The SRC and DST pointers in the task list must point to the last location in the corresponding buffer.
January 21, 2012
347
Texas Instruments-Production Data