TMS320C6474
SPRS552F – OCTOBER 2008 – REVISED JULY 2010
7.5
Enhanced Direct Memory Access (EDMA3) Controller
The primary purpose of the EDMA3 is to service user-programmed data transfers between two
memory-mapped slave endpoints on the device. The EDMA3 services software-driven paging transfers
(e.g., data movement between external memory and internal memory), performs sorting or subframe
extraction of various data structures, services event driven peripherals such as a McBSP port, and
offloads data transfers from the device CPU.
The EDMA3 includes the following features:
•
Fully orthogonal transfer description
– 3 transfer dimensions: array (multiple bytes), frame (multiple arrays), and block (multiple frames)
– Single event can trigger transfer of array, frame, or entire block
– Independent indexes on source and destination
•
Flexible transfer definition:
– Increment or FIFO transfer addressing modes
– Linking mechanism allows for ping-pong buffering, circular buffering, and repetitive/continuous
transfers, all with no CPU intervention
– Chaining allows multiple transfers to execute with one event
•
256 PaRAM entries
– Used to define transfer context for channels
– Each PaRAM entry can be used as a DMA entry, QDMA entry, or link entry
•
64 DMA channels
– Manually triggered (CPU writes to channel controller register), external event triggered, and chain
triggered (completion of one transfer triggers another)
•
8 Quick DMA (QDMA) channels
– Used for software-driven transfers
– Triggered upon writing to a single PaRAM set entry
•
6 transfer controllers and 6 event queues with programmable system-level priority
•
Interrupt generation for transfer completion and error conditions
•
Debug visibility
– Queue watermarking/threshold allows detection of maximum usage of event queues
– Error and status recording to facilitate debug
Each of the transfer controllers has a direct connection to the switched central resource (SCR).
lists the peripherals that can be accessed by the transfer controllers.
80
Peripheral Information and Electrical Specifications
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