PM8611-BIAP PMC [PMC-Sierra, Inc], PM8611-BIAP Datasheet - Page 274

• Manufacturer Part Number: PM8611-BIAP
• Manufacturer: PMC [PMC-Sierra, Inc]

14.2
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2010883, Issue 2
When configured as connecting to a link layer device, the JUST_REQ signal is an output
synchronized to OC1FP rather than IC1FP as shown in Figure 31. With the exception of the
JUST_REQ signal, the functional timing of the incoming SBI336 bus is the same when
connecting to a Link Layer device as connecting to a physical layer device.
Incoming 77 MHz TelecomBus Functional Timing
Figure 32 shows the timing of the Incoming TelecomBus stream when configured for 77.76 MHz
mode. Timing is provided by SREFCLK. SONET/SDH data is carried in the IDATA[7:0]. The
bytes are arranged in order of transmission in an STS-12/STM-4 stream. Each transport/section
overhead byte is labeled by Sx,y and type. Payload bytes are labeled by Sx,y and Bn, where ‘n’ is
the active offset of the byte. Within Sx,y, the STS-3/STM-1 number is given by ‘x’ and the
column number within the STS-3/STM-1 is given by ‘y’. The IPL signal is set high to mark
payload bytes and is set low at all other bytes. Similarly, ITPL is set high to mark tributary
payload bytes and is set low at all other bytes. The composite transport frame and payload frame
signal IJ0J1V1 is equivalent to the IC1FP in SBI mode and is set high with IPL set low to mark
the J0 byte of a transport frame. IC1J1V1/IC1FP is set high with IPL set high to mark the J1 bytes
and V1 multiframe of all the streams within IDATA[7:0]. The SBSLITE requires that all J1s
follow immediately after the J0(Z0) or the H3 overhead bytes and therefore ignores the IC1J1V1
signal during these 12 J1 locations. The SBSLITE also requires that all H4 multiframes be
aligned forcing all V1 bytes to follow the J1 bytes. Multiframe alignment is based on the first
V1 indication by IC1J1V1 after the twelve J1 bytes. Tributary path frame boundaries are marked
by a logic high on the IV5 signal. Tributaries in AIS alarm are indicated by the ITAIS signal.
The ICMP signal selects the active connection memory page in the memory switch. It is only
valid at the J0 byte position and is ignored at all other positions within the transport frame. The
connection memory page is switched on the next TelecomBus frame boundary after ICMP is
sampled at the J0 byte.
In Figure 32 below, STS-3/STM-1 numbers 1, 2, and 4 are configured for STS-3/AU3 operation.
STS-3/STM-1 number 3 is configured for STS-3c/AU4 operation. All streams are shown to have
an active offset of 522 by the high level on IPL and IC1J1V1/IC1FP at byte Sx,y/B522. No
pointer justifications are shown nor permitted by the SBSLITE. All stream are configured to carry
virtual tributaries/tributary units. The payload frame boundary of one such tributary is located at
byte S2,1/B0, as marked by a high level on IV5. At byte S2,2/B0, the tributary carried in stream
S2,2 (2 (STM-1 #2, AU3 #2) is shown to be in tributary path AIS by the high level on ITAIS
signal. The arrangement shown in Figure 32 is for illustrative purposes only; other
configurations, alarm conditions, active offsets and justification events, etc. are possible.
SBSLITE™ Telecom Standard Product Data Sheet
Preliminary
273