PM5347 datasheet(263/302 Pages) PMC

263 / 302 page

PM5347 S/UNI-PLUS

DATA SHEET

PMC-941033

ISSUE 6

SATURN USER NETWORK INTERFACE PLUS

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

247

Figure 29

- Path Overhead Insertion

TPOHFP

J1 byte

F2 byte

G1 byte

C2 byte

B3 byte

Z5 byte

Z4 byte

TPOHCLK

B3 byte

J1 byte

••••

TPOH

B2 B3 B4 B5 B6 B7 B8

TPOHEN

TPOHFP

The Path Overhead Insertion Timing Diagram (Figure 29) illustrates the path

overhead insertion interface. Output TPOHCLK is nominally a 576 kHz clock,

and is used to update output TPOHFP, and to sample inputs TPOH and

TPOHEN. In the figure, TPOHEN is held high throughout the eight bit positions

of the J1 byte. The eight bit values sampled on input TPOH are inserted in the

J1 byte position in the transmit stream. If TPOHEN was low during any of the 8

bit locations, the internally generated bit values of the corresponding bit positions

would be inserted in the J1 byte.

For the B3 byte position, an error insertion feature is provided. TPOHEN is held

high during bit positions 2, 5, 6, 7, and 8 of the B3 byte. The values sampled on

input TPOH are used as an error mask in the corresponding bit positions (2, 5, 6,

7, and 8) of the B3 byte in the transmit stream. If TPOH and TPOHEN are high

during a bit location, the corresponding bit of the internally generated B3 byte is

inverted before transmission.

PM5347 Datasheet(PDF) 263 Page - PMC-Sierra, Inc