Data Sheet
June 2001
DSP16410B Digital Signal Processor
Agere Systems Inc.
Agere Systems—Proprietary
Use pursuant to Company instructions
135
4 Hardware Architecture
(continued)
4.15 Parallel Interface Unit (PIU)
(continued)
4.15.1 Registers
(continued)
The
PA
register (
Table 78
) provides the DSP16410B memory address for any host accesses to DSP16410B mem-
ory. The host must access this register as two 16-bit quantities—the high half (
PAH
) and the low half (
PAL
). A core
accesses
PA
as a double-word (32-bit) location at address 0x41004. See
Figure 37
for details. As shown in
Table 78
, the ADD[19:0] field (
PA
[19:0]) contains the memory address to be accessed within the selected memory
component determined by the CMP[2:0] field (
PA
[22:20]). The ESEG[3:0] field (
PA
[26:23]) determines the external
segment extension for external memory accesses through the SEMI. The SEMI drives the value in the ESEG[3:0]
field onto the ESEG[3:0] pins at the same time that it asserts the appropriate enable pin (ERAMN, EION, or
EROMN) and drives the external memory address onto EA[18:0].
Table 78. PA (Parallel Address) Register
The memory address for this register is 0x41004. The application must choose either the host or one of the cores
to write this register.
31—27
26—23
22—20
Reserved
ESEG[3:0]
CMP[2:0]
32-Bit PA Register Host and DSP Access
Figure 37. 32-Bit PA Register Host and Core Access
19—0
ADD[19:0]
Bit
DSP
Access
PA
Host
Access
PAH
[15:0]
Field
Value
Definition
R/W
Reset
Value
0
0x0
31—27
26—23
Reserved
ESEG[3:0]
0
Reserved—write with zero.
External memory address extension. The value
of this field is placed directly on the ESEG[3:0]
pins for PIU accesses to external memory
§
.
The selected memory component is TPRAM0.
The selected memory component is TPRAM1.
Reserved.
The selected memory component is ERAM
,
EIO, or internal I/O.
Reserved.
Reserved.
The address within the selected memory space.
R/W
R/W
0x0
to
0xF
000
001
01X
100
22—20
CMP[2:0]
R/W
000
101
11X
19—16
15—0
ADD[19:0]
0x00000
to
0xFFFFF
R/W
0x00000
PAL
[15:0]
§
If the WEROM field (
ECON1
[11]—
Table 60 on page 110
) is set, EROM is selected in place of ERAM.
Write with
write_pal
command; read with
read_pal
command.
Memory-mapped to double word at address 0x41004.
Write with
write_pah
command; read with
read_pah
command.
This field is valid only for external memory accesses (CMP[2:0] = 100) and is ignored for internal memory accesses.
ADD[15:0]
ADD[19:16]
MEM[2:0]
ESEG[3:0]
Reserved
19—0
22—20
26—23
31—27
HOST ACCESSES
PA
[15:0] AS
PAL
[15:0] VIA
THE
read_pal
AND
write_pal
COMMANDS
HOST ACCESSES
PA
[31:16] AS
PAH
[15:0] VIA
THE
read_pah
AND
write_pah
COMMANDS
CORES ACCESS
PA
[31:0] AS DOUBLE-WORD MEMORY-MAPPED REGISTER AT LOCATION 0x41004
15
0
15
0