SBI Bus Serializer ASSP Telecom Standard Product Data Sheet
Released
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2000168, Issue 5
38
Pin Name
Type
Pin
No.
Function
payload and payload indicators appropriately for timing
adjustments.
JUST_REQ[1] can be part of either a 19.44MHz SBI
bus when combined with JUST_REQ[4:2] or can be
used as part of a standalone 77.76MHz SBI336 bus.
JUST_REQ[4:1] is configured as an input in Telecom
Bus mode and is ignored.
JUST_REQ[4:1] is asserted and sampled on the rising
edge of SREFCLK.
JUST_REQ[4:2] have integral pull-up resistors.
OACTIVE[4]
OACTIVE[3]
OACTIVE[2]
OACTIVE[1]
Output
AE23
V1
B5
D16
Outgoing Bus Active Indicator (OACTIVE[4:1]).
The
active high Outgoing SBI Bus Active Indicator signal,
OACTIVE[x], is asserted high during all octets when
driving data and control signals, ODATA[x][7:0],
ODP[x], OPL[x] and OV5[x], onto the bus.
All other SBI devices driving the bus listen to this signal
to detect multiple sources driving the bus which can
occur due to configuration problems.
OACTIVE[4:1] should only be used when the SBS is
configured for a 19.44MHz SBI bus. In all other modes,
OACTIVE[4:1] should be ignored.
When the SBS is held reset, OACTIVE[4:1] is driven
low.
OACTIVE[4:1] is updated on the rising edge of
SREFCLK.
ODETECT[4]
ODETECT[3]
ODETECT[2]
ODETECT[1]
Input
AD22
R2
C6
B17
Outgoing Bus Active Detector (ODETECT[4:1]).
This
input listens to the OR of all other SBI device ACTIVE
signals.
When another device is driving OACTIVE[x] high and
this device detects ODETECT[x] is high from that other
device it signals a collision and tristates the bus to
minimize or eliminate contention. Tristating is only done
with the 19.44MHz SBI buses.
The AND of OACTIVE[x] and ODETECT[x] is sampled
on the rising edge of SREFCLK to indicate that a
collision occurred and can be used to indicate
contention to management procedures.
ODETECT[4:1] is only valid when the SBS is configured
for a 19.44MHz SBI bus. ODETECT[4:1] must be held
low when configured for 19.44MHz Telecom bus. In all
other modes, ODETECT[4:1] is ignored.
ODETECT[4:1] have integral pull-up resistors.
OTPL[4]
OTPL[3]
OTPL[2]
OTPL[1]
Tristate
Output
AC20
V3
C8
B13
Outgoing Tributary Payload (OTPL[4:1]).
This signal
is used to indicate tributary payload when configured for
Telecom Bus and is held low when configured for SBI
or SBI336 buses.
OTPL[x] is set high during valid VC11 and VC12 bytes
of the corresponding Outgoing bus. OTPL[x] is set low
for all transport overhead bytes, high order path
overhead bytes, fixed stuff column bytes and tributary