PM5345 datasheet(67/196 Pages) PMC

67 / 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

10.13 Path Overhead Insert

The Path Overhead Insert Block provides a bit serial path overhead interface to

the TPOP. Any, or all of the path overhead bytes may be sourced from, or

modified by the bit serial path overhead stream, TPOH. The individual bits of

each path overhead byte are shifted in using the TPOHCLK output. The

TPOHFP output is provided to identify when the most significant bit of the Path

Trace byte is expected on TPOH. The state of the TPOHEN input, together with

an internal register, determines whether the data sampled on TPOH, or the

default path overhead byte values (shown in the table below) are inserted in the

STS-3c (STM-1) stream. For example, a high level on TPOHEN during the path

trace (J1) bit positions causes the eight values shifted in on TPOH to be inserted

in the J1 byte position in the STS-3c stream. A low level on TPOHEN during the

path trace bit positions causes the default value (0x00) to be inserted in the STS-

3c stream. Other combinations are also possible.

During the B3 and H4 byte positions in the TPOH stream, a high level on

TPOHEN enables an error insertion mask. While the error mask is enabled, a

high level on input TPOH causes the corresponding bit in the B3 or H4 byte to be

inverted. A low level on TPOH causes the corresponding bit in the B3 or H4 byte

to pass through the TPOP uncorrupted.

PM5345 Datasheet(PDF) 67 Page - PMC-Sierra, Inc