LM3S1627_16 Datasheet, PDF (269/727 Pages) Texas Instruments – Stellaris Microcontroller

Figure 7-2. Example of Ping-Pong DMA Transaction
μDMA Controller
SOURCE
Primary Structure DEST
transfers using BUFFER A
BUFFER A
Stellaris^® LM3S1627 Microcontroller
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
7.2.6.5
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.
July 17, 2014
269
Texas Instruments-Production Data