PM5345 datasheet(55/196 Pages) PMC

55 / 196 page

PM5345 S/UNI-155

DATA SHEET

PMC-930305

ISSUE 4

SATURN USER NETWORK INTERFACE

PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE

detected in bits 6, 7, and 8 of the K2 byte, for five consecutive frames. FERF is

removed when any pattern other than 110 is detected in bits 6, 7, and 8 of the

K2 byte for five consecutive frames. FERF is updated with timing aligned to

RCLK.

10.3.2 Line AIS Detect

The Line AIS Block detects the presence of a Line Alarm Indication Signal (AIS)

in the STS-3c stream. Output LAIS is asserted when a 111 binary pattern is

detected in bits 6,7,8 of the K2 byte, for five consecutive frames. LAIS is

removed when any pattern other than 111 is detected in bits 6, 7, and 8 of the

K2 byte for five consecutive frames. LAIS is updated with timing aligned to

RCLK.

10.3.3 Error Monitor

The Error Monitor Block calculates the received line BIP-24 error detection code

(B2) based on the line overhead and synchronous payload envelope of the STS-

3c (STM-1) stream. The line BIP-24 code is a bit interleaved parity calculation

using even parity. Details are provided in the references. The calculated BIP-24

code is compared with the BIP-24 code extracted from the STS-3c (STM-1) of

the following frame. Any differences indicate that a line layer bit error has

occurred. Up to 192000 (3 x 8 x 8000) bit errors can be detected per second in

an STS-3c (STM-1).

The Error Monitor Block accumulates these line layer bit errors in a 20 bit

saturating counter that can be read via the microprocessor interface. During a

read, the counter value is latched and the counter is reset to 0 (or 1, if there is an

outstanding event). Note, this counter should be polled at least once per second

to avoid saturation which in turn may result in missed bit error events.

The Error Monitor Block also accumulates line far end block error indications

(contained in the Z2 byte) in a similar manner.

10.4

Transport Overhead Extract Port

The Transport Overhead Extract Port ( also known as the Receive Transport

Overhead Access Port, RTOP) extracts the 81 bytes of receive transport

overhead and serializes them at 5.184 Mbit/s on RTOH for optional external

processing.

PM5345 Datasheet(PDF) 55 Page - PMC-Sierra, Inc