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
39
Pin Name
Type
Pin
No.
Function
transport overhead bytes (V1,V2,V3,V4).
OTPL[1] can be part of either a 19.44MHz Telecom Bus
when combined with OTPL[4:2] or can be used as part
of a standalone 77.76MHz Telecom Bus.
OTPL[4:2] are held tri-state when configured for
77.76MHz operation.
When the SBS is held reset, OTPL[4:1] is driven low.
OTPL[4:1] is updated on the rising edge of SREFCLK.
OTAIS[4]
OTAIS[3]
OTAIS[2]
OTAIS[1]
Tristate
Output
AE22
Y1
B7
B14
Outgoing Tributary Alarm Indication Signal
(OTAIS[4:1]).
This signal indicates tributaries in low
order path AIS state for the corresponding Outgoing
Telecom Bus and is held low when configured for SBI
or SBI336 buses.
OTAIS[x] is set high when the tributary on the
corresponding Outgoing bus is in AIS state and is set
low when the tributary is out of AIS state.
OTAIS[1] can be part of either a 19.44MHz telecom bus
when combined with OTAIS[4:2] or can be used as part
of a standalone 77.76MHz telecom bus.
OTAIS[4:2] are held tri-state when configured for
77.76MHz operation.
When the SBS is held reset, OTAIS[4:1] is driven low.
OTAIS[4:1] is updated on the rising edge of SREFCLK.
Incoming SBI Bus (56 Signals)
IC1FP[4]
IC1FP[3]
IC1FP[2]
IC1FP[1]
Input
T24
AE8
Y25
H3
Incoming C1 Frame Pulse (IC1FP[4:1]).
This signal
pulses high for one SREFCLK cycle to indicate the first
C1 octet on the incoming SBI or Telecom Bus.
In SBI/SBI336 mode:
This signal also indicates multi-frame alignment which
occurs every 4 frames, therefore this signal is pulsed
every fourth C1 octet to produce a 2KHz multi-frame
signal. The frame pulse does not need to be repeated
every 2KHz as the SBS will flywheel in its absence.
When using the SBI bus in synchronous mode the
IC1FP signal can be used to indicate T1 and E1 multi-
frame alignment by pulsing on 48 SBI frame
boundaries. This must be done if CAS is to be switched
along with the data.
For both 19.44MHz SBI and 77.76MHz SBI336 buses,
only IC1FP[1] is used and IC1FP[4:2] are ignored.
In Telecom bus mode:
This signal may also be pulsed to indicate the J1 byte
position and the byte following J1. For locked
STS/AUs, the J1 byte position must be locked to an
offset of either 0 or 522. The byte following J1 is used
to indicate multi-frame alignment and should only pulse
once every 4 frames marking the frame with the V1s.
IC1FP[1] can be part of either a 19.44MHz Telecom bus
when combined with IC1FP[4:2] or can be used as part
of a standalone 77.76MHz Telecom bus. When using