Texas Instruments TMS320DM643x manual External Memory Controller EMC, Internal DMA Idma

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Memory Controllers

2.3.4 External Memory Controller (EMC)

The external memory controller (EMC) is the hardware interface between the external memory map (external memory and external registers) and the other controllers in the C64x+ Megamodule (for example, L1P controller, L1D controller, and L2 controller). The EMC manages transfer operations between external memory and registers and the other memory controllers (L1P controller, L1D controller, and EMC).

EMC does not support the memory protection feature of the standard C64x+ Megamodule.

Refer to the TMS320C64x+ DSP Cache User’s Guide (SPRU862) and to the TMS320C64x+ DSP Megamodule Reference Guide (SPRU871) for more information on the EMC and for a description of its control registers.

2.3.5 Internal DMA (IDMA)

The internal DMA (IDMA) controller facilitates DMA transfers between any two internal memory-mapped locations. Internal memory-mapped locations include L1P, L1D, L2, and internal peripheral configuration registers.

Note: The IDMA cannot facilitate DMA to or from external memory-mapped locations. The EDMA facilitates external DMA transfers. Refer to Section 3.1 and to the TMS320DM643x DMP Enhanced Direct Memory Access (EDMA) Controller User's Guide (SPRU987) for information on EDMA.

The IDMA controller enables the rapid paging of data sections to any local memory-mapped RAM. A key advantage of the IDMA is that it allows paging between slower L2 and faster L1D data memory. These transfers take place without CPU intervention and without cache stalls.

Another key advantage is that you can use the IDMA controller to program internal peripheral configuration registers without CPU intervention.

Refer to the internal DMA (IDMA) controller section in the TMS320C64x+ DSP Megamodule Reference Guide (SPRU871) for more information on the IDMA controller and for a description of its control registers.

SPRU978E–March 2008 TMS320C64x+ Megamodule 21

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