Two-Dimensional Dma - Analog Devices ADSP-TS101 TigerSHARC Hardware Reference Manual

Two-Dimensional DMA

This section describes the changes in functionality that occur when the
TigerSHARC processor is placed in two-dimensional DMA mode.
Two-dimensional DMA mode is enabled by setting the
control register. This mode applies to external or internal
TCB DP
addresses.
Two-Dimensional DMA Channel Organization
In two-dimensional mode, two-dimensional DMA array addressing can be
performed on any DMA channel, receiver or transmitter.
The Index register (
array and maintains the current address by adding the X modify after each
transfer. The X Modify register (
to the current address to point to the next element in the X dimension
(next column). The X Count register (
both initially contain the number of words in the X dimension. The
register is used to reload
decremented after each transfer and contains the number of words left in
the current row.
The Y Modify register (
current address to point to the next element in the Y dimension (first loca-
tion in next row). When the X Count register reaches zero, this register is
added to the current address on the following cycle, and the Y Count reg-
ister is decremented. The value of
distance. The modify value in the Y modify field in the
16-bit signed integer, allowing both increments and decrements. The 16
bits are sign-extended when used with the 32-bit index register.
The Y Count register (
words in the Y dimension (number of rows) and is decremented each time
the X Count register reaches zero. When Y count reaches zero, the DMA
ADSP-TS101 TigerSHARC Processor
Hardware Reference
) is loaded with the first address in the data
TCB DI
TCB DX Modify
TCB DX Count
TCB DY Modify
TCB DY Modify
) initially contains the number of
TCB DY Count
Direct Memory Access
2DDMA
) contains the offset added
) and the
TCB DX Count
when it decrements to zero.
) contains the offset added to the
should be the row
TCB
bit in the
registers
CIX
DCIX
is
CX
register is a
DY
7-45