TMS320VC5501 Datasheet, PDF (58/193 Pages) Texas Instruments – TMS320VC5501 Fixed-Point Digital Signal Processor

Functional Overview
3.8 Direct Memory Access (DMA) Controller
The 5501 DMA provides the following features:
• Four standard ports for the following data resources: two for DARAM, one for Peripherals, and one for
External Memory
• Six channels, which allow the DMA controller to track the context of six independent DMA channels
• Programmable low/high priority for each DMA channel
• One interrupt for each DMA channel
• Event synchronization. DMA transfers in each channel can be dependent on the occurrence of selected
events.
• Programmable address modification for source and destination addresses
• Idle mode that allows the DMA controller to be placed in a low-power (idle) state under software control
The 5501 has an Auto-wakeup/Idle function for McBSP to DMA to on-chip memory data transfers when the
DMA and the McBSP are both set to IDLE. In the case that the McBSP is set to external clock mode and the
McBSP and the DMA are set to idle, the McBSP and the DMA can wake up from IDLE state automatically if
the McBSP gets a new data transfer. The McBSP and the DMA enter the idle state automatically after data
transfer is complete. [The clock generator (PLL) should be active and the PLL core should not be in
power-down mode for the Auto-wakeup/Idle function to work.]
The 5501 DMA controller allows transfers to be synchronized to selected events. The 5501 supports
14 separate synchronization events and each channel can be tied to separate synchronization event
independent of the other channels. Synchronization events are selected by programming the SYNC field in
the channel-specific DMA Channel Control Register (DMA_CCR).
The 5501 DMA can access all the internal DARAM space as well as all external memory space. The 5501 DMA
also has access to the registers for the following peripheral modules: McBSP, UART, GPIO, PGPIO, and I²C.
3.8.1 DMA Channel 0 Control Register (DMA_CCR0)
The DMA Channel 0 Control Register (DMA_CCR0) bit layouts are shown in Figure 3−11. DMA_CCR1 to
DMA_CCR5 have similar bit layouts. See the TMS320VC5501/5502 DSP Direct Memory Access (DMA)
Controller Reference Guide (literature number SPRU613) for more information on the DMA Channel n Control
Register (n = 0, 1, 2, 3, 4, or 5).
15
14
DSTAMODE
R/W, 00
13
12
SRCAMODE
R/W, 00
11
ENDPROG
R/W, 0
10
WP
R/W, 0
9
REPEAT
R/W, 0
8
AUTOINIT
R/W, 0
7
6
5
4
0
EN
PRIO
FS
R/W, 0
R/W, 0
R/W, 0
LEGEND: R = Read, W = Write, n = value at reset
SYNC
R/W, 00000
Figure 3−11. DMA Channel 0 Control Register Layout (0x0C01)
58 SPRS206H
December 2002 − Revised November 2004