PM8610-BIAP PMC [PMC-Sierra, Inc], PM8610-BIAP Datasheet - Page 83

• Manufacturer Part Number: PM8610-BIAP
• Description: SBS Telecom Standard Product Data Sheet Preliminary
• Manufacturer: PMC [PMC-Sierra, Inc]

10.16 Outgoing SBI336S Tributary Translator
10.16.1
10.17 Outgoing SBI336 Timing Adapter
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2000168, Issue 3
The SBI336S multiframe and signaling multiframe alignment is based a free running multiframe
counter that is reset with each C1FP character received. Under normal operating conditions each
received C1FP character will coincide with the free running multiframe counter. SBI336S
multiframe alignment is always required, SBI336S signaling multiframe alignment is optional
and only required when synchronous tributaries are supported with DS0 level switching.
The Outgoing SBI Tributary Translator block, OSTT, processes all timing information and
Channel Associated Signaling information for the tributaries on the outgoing SBI Bus or buses.
Input to this block is a 77 MHz SBI stream with all tributaries encoded in an internal format that
closely resembles the serial SBI format.
This block is transparent in TelecomBus mode.
This block translates the generic internal SBI format to the external SBI format. A control RAM
keeps the current configuration of the outgoing SBI bus(es) and the tributaries carried so that it
can perform the translation function.
Common to all tributaries is identification of the first C1 byte. There are unique mappings of the
8B/10B codes for the supported SBI bus link types: Asynchronous T1/E1, Synchronous (locked)
T1/E1, Transparent VT1.5/VT2, DS3/E3 and Fractional rate links. Much of the identification and
mapping of a link from serial SBI format is based on the OC1FP frame pulse and a tributaries
location relative to that C1 reference. In addition to the OC1FP identification this block identifies
multiframe alignment, valid payload, pointer movements for floating tributaries and timing
control for decoding from the 8B/10B serial SBI format.
The Outgoing SBI336 Timing Adapter, OSTA, provides a demultiplexing from a 77.76 MHz
SBI336 or TelecomBus to four outgoing 19.44 MHz SBI or TelecomBuses. The outgoing timing
adapter block also provides a transparent mode when the outgoing interface is already in 77.76
MHz SBI336 or TelecomBus format.
When the SBS is connected to a 19.44 MHz SBI link layer device the justification request signal,
JUST_REQ, is an output from the SBS and is aligned to the incoming bus. This block re-aligns
the internal justification request signal from the internal outgoing SBI336 frame alignment to the
incoming SBI frame alignment, marked by IC1FP. When the SBS is connected to a 19.44 MHz
SBI physical layer device or any 77.76 MHz SBI336 device, no re-alignment of the justification
request is required by this block.
Outgoing SBI336S Translation
SBS Telecom Standard Product Data Sheet
Preliminary
83