PMC-Sierra, Inc.
PM5356
S/UNI-622-MAX
DATASHEET
S/UNI-622-MAX
PMC-1980589
ISSUE 5
SATURN USER NETWORK INTERFACE (622-MAX)
9.5
Microprocessor Interface Signals
Pin Name
Type
Pin
No.
Function
CSB
Input
C11
The active-low chip select (CSB) signal is low during S/UNI-622-
MAX register accesses.
When CSB is high, the RDB and WRB inputs are ignored.
When CSB is low, the RDB and WRB are valid. CSB must be
high when RSTB is low to properly reset the chip.
If CSB is not required (i.e., registers accesses are controlled
using the RDB and WRB signals only), CSB must be connected
to an inverted version of the RSTB input.
RDB
Input
Input
I/O
B11
A11
The active-low read enable (RDB) signal is low during S/UNI-
622-MAX register read accesses. The S/UNI-622-MAX drives
the D[7:0] bus with the contents of the addressed register while
RDB and CSB are low.
WRB
The active-low write strobe (WRB) signal is low during a S/UNI-
622-MAX register write accesses. The D[7:0] bus contents are
clocked into the addressed register on the rising WRB edge
while CSB is low.
D[0]
D[1]
D[2]
D[3]
D[4]
D[5]
D[6]
D[7]
B17
A17
C16
B16
C15
B15
A15
D14
The bi-directional data bus D[7:0] is used during S/UNI-622-
MAX register read and write accesses.
A[0]
A[1]
A[2]
A[3]
A[4]
A[5]
A[6]
A[7]
Input
B14
A14
D13
C13
B13
A13
C12
B12
The address bus A[7:0] selects specific registers during S/UNI-
622-MAX register accesses.
A[8]
Input
D11
The test register select (A[8]) signal selects between normal and
test mode register accesses. A[8] is high during test mode
register accesses, and is low during normal mode register
accesses. A[8] may be tied low.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
30
PMC [ PMC-SIERRA, INC ]
