Auto-Initialization Sequence With Unchanging Context (Repeat = 1) - Texas Instruments OMAP5910 Reference Manual

DSP DMA
Figure 70.

Auto-Initialization Sequence With Unchanging Context (REPEAT = 1)

7.2.4.2 Auto-Initialization With Changing Context
130 DSP Subsystem
The DSP core
programs desired
channel context into the
configuration registers
The DSP core sets
AUTOINIT=1 and
REPEAT=1 to select the
correct auto-initialization
mode
The DSP core sets EN=1
to enable the DMA channel
If the desired context for the channel needs to be repeated and is not the same
on each block transfer, then the DMA controller must be configured with
AUTOINIT = 1 and REPEAT = 0. When REPEAT = 0, the DMA controller
waits for the DSP core to write ENDPROG = 1 before it copies the
configuration registers. This provides handshaking for the DMA controller to
prevent it from copying the registers while they are still being configured by the
DSP core. Figure 71 shows a detailed sequence of events in this mode.
The DMA controller
transfers the block of data
according to the channel
context
When the block transfer is
complete, the DMA disables
the channel (EN = 0) and
recopies the configuration
registers to the working
registers
The DMA controller
reenables the channel
(EN = 1)
SPRU890A