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
346
The use of RJUST_REQ on the receive SBI336 interface is dependent on whether the SBS is
configured as connecting to a physical layer device or link layer device. The interface
connection type refers to the Incoming and Outgoing SBI buses therefore the configuration of
the receive SBI336 interface is opposite to that of the Outgoing SBI336 bus. In Figure 39
RJUST_REQ is shown as a receive SBI336 bus input which is consistent with the SBS
configured for connection to a link layer device, meaning that the receive SBI336 interface is
expected to connect to a physical layer type device. When the SBS is configured for connection
to a physical layer device, RJUST_REQ is not used.
Figure 39 Receive SBI336 Functional Timing
C1
V3
V3
DS0#9 V3
DS0#4 V5
DS0#2DS0#7
valid
SYSCLK
RC1FP
RPL
RV5
RDATA[7:0]
RDP
RJUST_REQ
OCMP
14.10 Receive Serial LVDS Functional Timing
Figure 40 below shows the relative timing of the receive LVDS links. Links carry
SONET/SDH or SBI336 frame octets that are encoded in 8B/10B characters. Frame
boundaries, tributary justification events and tributary alarm conditions are encoded in special
control characters. The upstream devices sourcing the links share a common clock and have a
common transport frame alignment that is synchronized by the Receive Serial Interface Frame
Pulse signal (RC1FP). Due to phase noise of clock multiplication circuits and backplane
routing discrepancies, the links will not be phase aligned to each other (within a tolerance level
of 24 byte times) but are frequency locked The delay from RC1FP being sampled high to the
first and last C1 character is shown in Figure 40. In this example, the first C1 is delivered by
the working link (RNWRK/RPWRK). The delay to the last C1 represents the time when both
links have delivered their C1 character. The minimum value for the internal programmable
delay (RC1FPDLY[13:0]) is the delay to the last C1 character plus 15. The maximum value is
the delay to the first C1 character plus 31. Consequently, the external system must ensure that
the relative delays between all the receive LVDS links be less than 16 bytes. The relative
phases of the links in Figure 40 are shown for illustrative purposes only.