Data Sheet
June 2001
DSP16410B Digital Signal Processor
134
Agere Systems—Proprietary
Use pursuant to Company instructions
Agere Systems Inc.
4 Hardware Architecture
(continued)
4.15 Parallel Interface Unit (PIU)
(continued)
4.15.1 Registers
(continued)
The
PDI
and
PDO
registers (
Table 74
and
Table 75
) are the 16-bit PIU input and output data registers.
PDI
con-
tains data written by the host at the conclusion of a valid host write cycle.
PDO
contains data written by a core or
the DMAU that is driven onto the PIU data bus during a valid host read cycle.
Table 74. PDI (PIU Data In) Register
The memory address for this register is 0x41008.
Table 75. PDO (PIU Data Out) Register
The memory address for this register is 0x4100A. For a typical application, the DMAU writes
PDO
, but the cores
can also write
PDO
. The application must ensure that these entities do not write
PDO
at the same time.
31—16
Reserved
The
DSCRATCH
and
HSCRATCH
registers (
Table 77
and
Table 76
) are the DSP and host scratch registers that
can be used to pass messaging data between a core and the host. After a core writes 16-bit data to
DSCRATCH
,
the host can read this data by issuing a
read_dscratch
command. Conversely, the host can write 16-bit data to
HSCRATCH
by issuing a
write_hscratch
command. See
Section 4.15.5 on page 144
for details on host com-
mands.
Table 76. HSCRATCH (Host Scratch) Register
The memory address for this register is 0x41006.
Table 77. DSCRATCH (DSP Scratch) Register
The memory address for this register is 0x41002. The application must choose one of the cores to write
DSCRATCH
.
31—16
Reserved
31—16
Reserved
15—0
PIU Input Data
Bit
Field
Reserved
PIU Input Data
Description
R/W (Cores)
R
R
R/W (Host)
W
W
Reset Value
0
0
31—16
15—0
Reserved—read as zero.
PIU data in from host.
15—0
PIU Output Data
Bit
Field
Reserved
PIU Output Data PIU data out to host.
Description
R/W (Cores)
R/W
R/W
R/W (Host)
R
R
Reset Value
0
0
31—16
15—0
Reserved—write with zero.
31—16
Reserved
15—0
Host Scratch
Bit
Field
Reserved
Host Scratch
Description
R/W (Cores)
R
R
R/W (Host)
W
W
Reset Value
0
0
31—16
15—0
Reserved—read as zero.
Host scratch data to DSP16410B.
15—0
DSP Scratch
Bit
Field
Reserved
DSP Scratch
Description
R/W (Cores)
R/W
R/W
R/W (Host)
R
R
Reset Value
0
0
31—16
15—0
Reserved—write with zero.
DSP scratch data to host.