PEF80912HV14XT Lantiq, PEF80912HV14XT Datasheet - Page 26

• Manufacturer Part Number: PEF80912HV14XT
• Manufacturer: Lantiq

Specifications of PEF80912HV14XT

• Lead Free Status / Rohs Status: Supplier Unconfirmed

•
Figure 8
2.3.2
An error monitoring function is implemented covering the 2B + D and M4 data
transmission of a U-superframe by a Cyclic Redundancy Check (CRC).
The computed polynomial is:
The check digits (CRC bits CRC1, CRC2, …, CRC12) generated are transmitted in the
U-superframe. The receiver will compute the CRC of the received 2B + D and M4 data
and compare it with the received CRC-bits generated by the transmitter.
A CRC-error will be indicated to both sides of the U-interface, as a NEBE (Near-end
Block Error) on the side where the error is detected, as a FEBE (Far-end Block Error) on
the remote side. The FEBE-bit will be placed in the next available U-superframe
transmitted to the originator.
2.3.3
The scrambling algorithm ensures that no sequences of permanent binary 0s or 1s are
transmitted. The scrambling / descrambling process is controlled fully by the Q-
SMINT
Data Sheet

O. Hence, no influence can be taken by the user.
2B1Q Decoding
Cyclic Redundancy Check / FEBE bit
Scrambling/ Descrambling
U
2B1Q
(M-bit handling acc. to ETR080)
U
2B1Q
Deframer - Data Flow Scheme
M
D
E
U
X
-Deframer
Control
G (u) = u
Sync/Inv. Sync
Descrambler
(+ modulo 2 addition)
12
+ u
11
18
+ u
D
M
U
E
X
3
+ u
2
+ u + 1
D
M
U
E
X
CRC Check
Functional Description
PEF 80912/80913
M5,6 except CRC
2B+D
M1,2,3 (EOC)
M4
udeframer.emf
2001-03-29