Data Sheet
June 2001
DSP16410B Digital Signal Processor
Agere Systems Inc.
Agere Systems—Proprietary
Use pursuant to Company instructions
83
4 Hardware Architecture
(continued)
4.13 Direct Memory Access Unit (DMAU)
(continued)
4.13.3 Data Structures
(continued)
4.13.3.2 Two-Dimensional Data Structure (SWT Channels)
Figure 21
illustrates the structure of a two-dimensional double-buffered array for an SWT channel. This structure is
useful for TDM channel multiplexing and demultiplexing. The array consists of ncolumns (double buffers), each
containing 2rrows (elements). The columns are typically contiguous (back-to-back) in memory, but this is not
required. See
Section 4.13.5
for more information about SWT channels. See
Section 4.13.9.1
for an example of a
transfer using a two-dimensional array.
A Two-Dimensional Data Structure for Double-Buffering n Channels
Figure 21. Two-Dimensional Data Structure for Double-Buffering nChannels
Two-dimensional data structures for data transfers use
address, base, limit, counter, stride, reindex, and con-
trol registers associated with the SWT channel carrying
the data between an SIU and memory.
CTL
0—3
The user software must initialize the cor-
responding control register with the POSTMOD[1:0]
field programmed to 0x1 to enable two-dimensional
array accesses, the SIGCON[2:0] field programmed to
a value that defines when interrupts are generated, and
the AUTOLOAD field set to one so that no further core
interaction is needed.
DADD
0—3
and
SADD
0—3
must initialize the corresponding destination and
source address registers to the top of the input (desti-
nation) and output (source) arrays located in
The user software
memory. The DMAU automatically updates these reg-
isters in a row-major order as the transfer proceeds.
DBAS
0—3
and
SBAS
0—3
must also initialize the corresponding destination and
source base registers to the top of the input (destina-
tion) and output (source) arrays located in
memory. These registers are used with the autoload
feature of the associated SWT channel.
The user software
C
C
R
0
S
0
SBAS
0—3
SOURCE
ARRAY
COMPLETE
SOURCE
FRAME
COMPLETE
A
DESTINATION
ARRAY COMPLETE
(SIGCON=0x5)
DESTINATION
FRAME COMPLETE
(SIGCON=0x2)
OUTPUT SOURCE ARRAY
INPUT DESTINATION ARRAY
S
SOURCE
BUFFER
COMPLETE
DESTINATION
BUFFER COMPLETE
(SIGCON=0x3)
B
D
B
ROW=0
ROW=1
ROW=2r–1
ROW=r–1
C
ROW=0
ROW=1
ROW=2r–1
ROW=r–1
ROW=0
ROW=1
ROW=2r–1
ROW=r–1
C
C
R
0
S
0
DBAS
0—3
A
S
B
D
B
ROW=0
ROW=1
ROW=2r–1
ROW=r–1
C
ROW=0
ROW=1
ROW=2r–1
ROW=r–1
ROW=0
ROW=1
ROW=2r–1
ROW=r–1