LM3S5737 Datasheet, PDF (293/833 Pages) Texas Instruments – Stellaris® LM3S5737 Microcontroller

Stellaris® LM3S5737 Microcontroller
Refer to Figure 8-2 on page 293 for an example showing operation in Ping-Pong mode.
Figure 8-2. Example of Ping-Pong DMA Transaction
μDMA Controller
SOURCE
Primary Structure DEST
transfers using BUFFER A
BUFFER A
Cortex-M3 Processor
Peripheral/uDMA _Interrupt
SOURCE
Alternate Structure DEST
transfers using BUFFER B
BUFFER B
Peripheral/uDMA _Interrupt
SOURCE
Primary Structure
DEST
transfers using BUFFER A
BUFFER A
Peripheral/uDMA _Interrupt
SOURCE
Alternate Structure DEST
transfers using BUFFER B
BUFFER B
· Process data in BUFFER A
· Reload primary structure
· Process data in BUFFER B
· Reload alternate structure
· Process data in BUFFER B
· Reload alternate structure
8.2.6.5
Memory Scatter-Gather
Memory Scatter-Gather mode is a complex mode used when data needs to be transferred to or
from varied locations in memory instead of a set of contiguous locations in a memory buffer. For
example, a gather DMA operation could be used to selectively read the payload of several stored
packets of a communication protocol, and store them together in sequence in a memory buffer.
November 17, 2011
293
Texas Instruments-Production Data