PM8610-BIAP PMC [PMC-Sierra, Inc], PM8610-BIAP Datasheet - Page 310

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

14.2
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2000168, Issue 3
When configured as connecting to a link layer device the JUST_REQ[1] signal is an output
synchronized to OC1FP rather than IC1FP as shown in Figure 32. With the exception of the
JUST_REQ[1] 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 SBI Bus Functional Timing
Figure 33 shows the functional timing for the four incoming SBI buses. When in SBI mode
SREFCLK is a 19.44 MHz clock sourced from SREFCLK19 which is generated from SYSCLK.
Figure 33 shows the timing for a 19.44 MHz SBI bus configured as connecting to a link layer
device carrying three E3 links. When configured for SBI mode connecting to a link layer device
the JUST_REQ[x] signal is an output synchronized to IC1FP. All other signals in Figure 33 are
inputs.
The first occurrence of IPL[x] in Figure 33 shows a negative timing justification during the H3
octet. During this H3 octet there would be actual data for E3#2. The IV5[x] signal would be
asserted during any octet carrying a V5 payload indicator. JUST_REQ[x] in this timing diagram
indicates to the link layer device that it should do a positive timing justification on tributary E3#3
and a negative timing justification on tributary E3#2 during the next SBI frame.
With the SBI bus there is also an ACTIVE signal that indicates when a particular SBI device is
driving the bus. In Figure 33 the link layer device is configured for E3#2 and E3#3 as indicated
by ACTIVE going high during these tributaries.
Figure 33 Incoming SBI Functional Timing
JUST_REQ[x]
When configured as connecting to physical layer device, JUST_REQ[x] is an input synchronized
to OC1FP, therefore JUST_REQ[x] would not be included in the incoming SBI functional timing
diagram when configured for connecting to a physical layer device.
IDATA[x][7:0]
SREFCLK19
SREFCLK
SYSCLK
ACTIVE
IC1FP
IDP[x]
IPL[x]
IV5[x]
ICMP
valid
C1
H3
H3
SBS Telecom Standard Product Data Sheet
H3
E3 #1
E3 #2
E3 #3
Preliminary
E3 #1
310