PEF82912FV1.4 Infineon Technologies, PEF82912FV1.4 Datasheet - Page 93

• Manufacturer Part Number: PEF82912FV1.4
• Description: ISDN Interface ISDN
• Manufacturer: Infineon Technologies

Specifications of PEF82912FV1.4

• Mounting Style: SMD/SMT
• Package / Case: MQFP-64
• Lead Free Status / Rohs Status: Details

PEF 82912/82913
Functional Description
2.4.6
Cyclic Redundancy Check / FEBE bit
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:
12
11
3
2
G (u) = u
+ u
+ u
+ u
+ u + 1
(+ modulo 2 addition)
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.
Figure 44
illustrates the CRC-process.
Data Sheet
79
2001-03-30