
Multi-Service Access Device For Channelized Interfaces
Telecom Standard Product Data Sheet
Production
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990823, Issue 4
618
15.4
Outgoing Parallel TelecomBus
Figure 32 shows the timing of the Outgoing TelecomBus interface. Timing is provided by
SYSCLK. SONET/SDH data is carried in the OD[
X
][7:0], where ‘
X
’ denotes one of the four
sections of the Outgoing TelecomBus. The bytes are arranged in order of transmission in an STS-
12/STM-4 stream. The OWTI block can be used to rearrange timeslots between the system side
and the line side of the S/UNI-MACH48.
The timeslot naming strategy and assignment is shown in Figure 32. 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 OPL[
X
] signal is set high to mark
payload bytes and is set low at all other bytes. All four OJ0J1[4:1] signals are set high with all
four OPL[4:1] signals set low to mark the J0 byte of a transport frame. OJ0J1[
X
] is set high with
OPL[
X
] also set high to mark the J1 byte of all the streams within OD[
X
][7:0]. High order
streams in alarm are indicated by the OALARM[
X
] signal which is set on a per-channel basis
using the TCAS12 CH
x
_OALARM register bits. For Figure 32 OJ0REFDLY[13:0] is set to all
zeros.
In Figure 32, timeslots S1,x, S2,y, and S4,z are configured for STS-1/STM-0 operation. Timeslot
S3,n is configured for STS-3c/STM-1 operation. Stream S1,1 (STM-1 #1, AU3 #1) is shown to
have an active offset of 522 by the high level on OPL[
X
] and OJ0J1[
X
] at byte S1,1/B522.
Stream S2,1 (STM-1 #2, AU3 #1) is shown to be in high-order path alarm (OALARM[
X
] set high
at bytes S2,1/Z0, S2,1/B522, S2,1/H3 and S2,1/B0). STM-1 #3 is configured in AU4 mode and is
shown to have an active offset of 0 by the high level on OPL[
X
] and OJ0J1[
X
] at byte S1,3/B0.
For the case where an STS-48c/STM-16c is carried on the four buses
OD[4:1][7:0], the J0
indication is given on all four buses (OJ0J1[4:1] = 1 and OPL[4:1] = 0) at the same time. The J1
indication is given only on the first bus (OJ0J1[1] = 1 and OPL[1] = 1, OJ0J1[4:2] = 0 and
OPL[1] = 1).
OCMP is sampled at the clock cycle where the J0 indication is given (OJ0J1[
X
] is logic 1 and
OPL[
X
] is logic 0). OCMP is used to select the incoming memory page in the OWTI when the
parallel TelecomBus is in use.
The arrangement shown in Figure 32 is for illustrative purposes only; other configurations, alarm
conditions, active offsets and justification events, etc. are possible.