
PRELIMINARY
INVERSE MULTIPLEXING OVER ATM
PM7341 S/UNI-IMA-84
DATASHEET
PMC-2000223
ISSUE 4
INVERSE MULTIPLEXING OVER ATM
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
65
Pin Name
Type
Pin
No.
Function
AACTIVE
Output
K4
The
Add Bus Active Indicator (AACTIVE)
is an
active high signal that is asserted during all octets
when driving data and control signals - ADATA[7:0],
ADP, APL and AV5 – onto the Add bus.
All other SBI Link Layer devices (e.g., other S/UNI-
IMA-84s on the SBI bus) driving the Add bus listen to
this signal to detect multiple sources driving the Add
bus, which can occur due to configuration problems
The AACTIVE output is asserted on the rising edge
of REFCLK.
ADETECT
Input
N3
The
Add Bus Active Detector (ADETECT)
signal
indicates when another device is driving the Add
bus. Other Link Layer device AACTIVE outputs can
be externally OR’ed together and connected to
ADETECT.
When the S/UNI-IMA-84 is driving AACTIVE high
and simultaneously detects ADETECT is high, it
tristates its Add bus outputs to minimize or eliminate
contention.
ADETECT is an asynchronous signal which is used
to disable the tristate drivers on the ADD bus. The
AND of AACTIVE and ADETECT is used. to indicate
that a collision has occurred.
This input must be tied low when not used.
9.9 General (5 signals)
Pin Name
Type
Pin
No.
Function
RSTB
Input
AE22
The
Reset Bar
(RSTB) is an active low signal that
provides an asynchronous S/UNI-IMA-84 reset.
RSTB is a Schmitt-triggered input with an internal
pull-up resistor.