Receive Restart Or Finish - Analog Devices ADSP-BF506F Hardware Reference Manual

Functional Description
restriction is satisfied. This implies that any work unit which might be
managed by
Restart
DMAx_CURR_Y_COUNT
Particularly if the
programmed to 0 (representing 65,536 transfers, the maximum value) the
channel will operate properly for 1-D work units up to 65,531 data items
or 2-D work units up to 4,294,967,291 data items.

Receive Restart or Finish

No or
Restart
nel configured for memory write unless either the peripheral has already
performed at least five DMA transfers in the current work unit or the pre-
vious work unit was terminated by a
has performed at least one DMA transfer in the current work unit. If five
data transfers have been performed, then at least one data item has been
written to memory in the current work unit, which implies that the cur-
rent work unit's descriptor fetch completed before the data grant of the
fifth item. Otherwise, if less than five data items have been transferred, it
is possible that all of them are still in the DMA FIFO and the previous
work unit is still in the process of completion and transition between work
units.
Similarly, if a
Finish
one subsequent DMA data transfer has occurred, then the fact that the
DMA channel issued the grant guarantees that the previous work unit has
already completed the process of draining its data to memory and transi-
tioning to the new work unit.
If a peripheral terminates all work units with the
tively assuming responsibility for all work unit boundaries for the DMA
channel), then the peripheral need only ensure that it performs a single
transfer in each work unit before any restart or finish. This requires, how-
ever, that the user programs the descriptors for all work units managed by
the channel with
7-36
or commands must have
Finish
values representing at least five data items.
DMAx_CURR_X_COUNT
command may be issued by a peripheral to a chan-
Finish
command ended the previous work unit and at least
DMAx_CURR_X_COUNT
ADSP-BF50x Blackfin Processor Hardware Reference
DMAx_CURR_X_COUNT
/
DMAx_CURR_Y_COUNT
command and the peripheral
Finish
Finish
/
DMAx_CURR_Y_COUNT
/
registers are
opcode (effec-
values repre-