DMA Controller
3-16
3.4
DMA Controller
Acting in the background of MPU operation, the DSP DMA controller can:
-
Transfer data among internal memory, external memory, and peripherals
residing on the DSP public peripheral bus
-
Transfer data between the MPUI and internal memory
Figure 3–7 shows the ports serviced by the DMA controller within the context
of the DSP subsystem.
3.4.1
Key Features of the DMA Controller
The DMA controller has the following important features:
-
Operation independent of the MPU
-
Four standard ports, one for each data resource: DARAM, SARAM, exter-
nal or shared system memory via DSP EMIF, and peripherals via the
shared TIPB bridge
-
An auxiliary port to enable certain transfers between the MPUI and
memory
-
Six logical channels, which allow the DMA controller to keep track of the
context of six independent block transfers plus a seventh logical channel
for MPUI transfers
-
Bits for assigning each channel a low priority or a high priority.
-
Event synchronization. DMA transfers in each channel can be made
dependent on the occurrence of selected events.
-
An interrupt for each channel. Each channel can send an interrupt to the
DSP CPU on completion of certain operational events.
-
Software-selectable options for updating addresses for the sources and
destinations of data transfers.
The DMA controller performs data transfers between the following source and
destination ports:
-
Single-access RAM and SARAM port
-
Dual-access RAM and DARAM port
-
External memory and EMIF port
-
TI peripheral bus and PERIPH port
-
MPUI interface and MPUI port