Data Sheet
June 2001
DSP16410B Digital Signal Processor
136
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 host accesses
PAH
and
PAL
by executing the
read_pah
,
read_pal
,
write_pah
, and
write_pal
commands.
After certain host commands, the PIU autoincrements the value in
PA
. See
Section 4.15.5 on page 144
for details
on host commands. Unlike the DSP1620 and DSP16210 MIOU, the PIU increments the value in the
PA
register
linearly and does not wrap it.
4.15.2 Hardware Interface
The host interface to the PIU consists of 29 pins, as summarized in
Table 79
. The remainder of this section
describes these pins in detail.
Table 79. PIU External Interface
Function
Address and
Data
Enables and
Strobes
.
Pin
Type
I/O/Z 16-bit bidirectional, parallel data bus. 3-stated if PCSN = 1.
I
PIU 4-bit address and control input.
I
PIU output data strobe.
Intelhost: Connect to the host active-low read data strobe.
Motorolahost: Connect to the host data strobe.
I
PIU input data strobe.
Intelhost: Connect to the host active-low write data strobe.
Motorolahost: Connect to logic 0 to program an active-high data strobe. Connect to
logic 1 to program an active-low data strobe.
I
PIU read/write not.
Intelhost: Connect to the host active-low host write strobe.
Motorolahost: Connect to host RWN strobe.
I
PIU chip select—active-low.
O
PIU output buffer empty flag.
O
PIU input buffer full flag.
O
PIU interrupt (interrupt signal to host).
O
PIU ready.
Indicates the status of the current host read operation or previous host write operation.
The PRDYMD pin determines the logic level of this pin.
I
PIU ready pin mode.
0: PRDY pin is active-low (PRDY = 0 indicates the PIU is ready).
1: PRDY pin is active-high (PRDY = 1 indicates the PIU is ready).
Description
PD[15:0]
PADD[3:0]
PODS
PIDS
PRWN
PCSN
POBE
PIBF
PINT
PRDY
Flags, Interrupt,
and Ready
PRDYMD
If the system application does not use these pins, they must be tied low.
If the system application does not use these pins, they must be tied high.