Stop Mode; Autobuffer Mode; Two-Dimensional Dma Operation - Analog Devices ADSP-BF506F Hardware Reference Manual

Stop Mode

In stop mode, the DMA operation is executed only once. When started,
the DMA channel transfers the desired number of data words and stops
itself when the transfer is complete. If the DMA channel is no longer used,
software should clear the
channel. Stop mode is entered if the
register is 0. The
DMAx_CONFIG
For receive (memory write) operation, the
the same as the inverted
tion, however, the two bits have different timing. Refer to the description
of the bit in the
SYNC

Autobuffer Mode

In autobuffer mode, the DMA operates repeatedly in a circular manner. If
all data words have been transferred, the address pointer
is reloaded automatically by the
also be generated.
Autobuffer mode is entered if the
is 1. The
NDSIZE

Two-Dimensional DMA Operation

Register-based and descriptor-based DMA can operate in one-dimensional
mode or two-dimensional mode.
In two-dimensional (2-D) mode, the DMAx_X_COUNT register is
accompanied by the DMAx_Y_COUNT register, supporting arbitrary
row and column sizes up to 64K × 64K elements, as well as arbitrary
DMAx_X_MODIFY and DMAx_Y_MODIFY values up to ±32K bytes.
Furthermore, DMAx_Y_MODIFY can be negative, allowing implementa-
tion of interleaved datastreams. The DMAx_X_COUNT and
ADSP-BF50x Blackfin Processor Hardware Reference
enable bit to disable the otherwise paused
DMAEN
NDSIZE
bit. For transmit (memory read) opera-
DMA_DONE
register for details.
DMAx_CONFIG
DMAx_START_ADDR
FLOW
bit must be 0 in autobuffer mode.
Direct Memory Access
bit field in the DMA channel's
FLOW
field must always be 0 in this mode.
bit functions almost
DMA_RUN
value. An interrupt may
field in the
DMAx_CONFIG
DMAx_CURR_ADDR
register
7-11