PM8611-BIAP PMC [PMC-Sierra, Inc], PM8611-BIAP Datasheet - Page 47

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

10.1.8
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2010883, Issue 2
DS3 asynchronous timing is compensated via the H3 octet as described in section 10.1.2. DS3
link rate adjustments are optionally passed across the SBI via the Linkrate octet as described in
section 10.1.3. DS3 alarm conditions are optionally passed across the SBI bus via the Linkrate
octet as described in Sections 10.1.3 and 10.1.4.
E3 Tributary Mapping
Table 15 shows a E3 tributary mapped within the first SPE, SPE1. The V5 indicator pulse
identifies the V5 octet. The E3 framing format does not follow an 8 KHz frame period so the
floating frame located by the V5 indicator and shown in grey in Table 15, will jump around
relative to the H1 frame on every pass. In fact the V5 indicator will be asserted two or three times
per H1 frame, as is shown by the second and third V5 octet in Table 15. The V5 indicator and
payload signals indicate negative and positive rate adjustments which are carried out by either
putting a data byte in the H3 octet or leaving empty the octet after the H3 octet.
Table 15 E3 Framing Format
Because the E3 tributary rate is less than the rate of the grey region, padding octets are
interleaved with the E3 tributary to make up the difference in rate. Interleaved with every E3
frame is an alternating pattern of 81 and 82 stuff octets, one of which is the V5 octet. These 81 or
82 stuff octets are spread evenly across the E3 frame. Each E3 subframe is 48 octet which is
further broken into 4 equal blocks of 12 octets each. Table 16 shows the alternating E3 frame
stuffing format that is packed into the grey region of Table 15. Note that there are 6 stuff octets
after the V5 octet in one frame and 5 stuff octets after the V5 octet in the next frame. In this table
V5 indicates the V5 octet which is also a stuff octet, R indicates a stuff octet, D indicates an E3
data octet, FAS indicates the first byte of the 10 bit E3 Frame Alignment Signal.
ROW
1
2
3
4
5
6
7
8
9
SPE
COL #
SBI
COL#
1,4,7,10
Unused H1
Unused H2
Unused H3
Unused Linkrat
Unused Unused E3
Unused Unused E3
Unused Unused E3
Unused Unused E3
Unused Unused E3
13
e
E3
1
16
V5
E3
E3
E3
E3
2-18
E3
E3
E3
E3
E3
E3
E3
E3
E3
E3
19
70
E3
E3
E3
V5
E3
E3
E3
E3
E3
E3
20-
38
E3
E3
E3
E3
E3
E3
E3
E3
E3
E3
39
130
E3
E3
E3
E3
E3
E3
V5
E3
E3
SBSLITE™ Telecom Standard Product Data Sheet
E3
40-
84
E3
E3
E3
E3
E3
E3
E3
E3
E3
E3
85
268
E3
E3
E3
E3
E3
E3
E3
E3
E3
Preliminary
46