CX28343 View Datasheet(PDF) - Unspecified

Part Name

Description

MFG CO.

CX28343

(CX2834x) Dual / Triple / Quad / Hex / Octal - Enhanced DS3 / E3 Framer

Unspecified 

Appendix B: Frame Structure

Summary

\As per ANSI T1.107-1995 and ITU-T G.704-1995, in DS3 mode, a frame is

composed of 4760 bits, of which, 4704 (4697 in M13/M23) form the payload, while

56 (63 in M13/M23) are overhead bits. The overhead bits are divided into several

fields, which are described in Table B-1.

Table B-1. Overhead Bits in DS3 Mode

Field

Description

3 M-bits

28 F-bits

2 X-bits

2 P-bits

Bits 2721, 3401 & 4081 for framing, bearing a “010” pattern

Every 170 bits, from bit 86 to bit 4676 for subframing, bearing a “1001”x7 pattern

Bits 1 and 681 for remote alarm indication (RAI), bearing a “11” pattern to signal error-free conditions, a “00”

pattern to signal RAI

Bits 1361 and 2041 for parity, bearing a “11” pattern if the digital sum of all the 4704 payload bits of the

preceding frame equals 1, a “00” pattern if it equals 0

In DS3 M13/M23 Mode Only

21 C-bits

Bits 171, 341, 511, 851, 1021, 1191, 1531, 1701, 1871, 2211, 2381, 2551, 2891, 3061, 3231, 3571, 3741,

3911, 4251, 4421, and 4591 for justification control bits of the payload data channels

7 stuff

Bits 597, 1278, 1959, 2640, 3321, 4002, and 4683

opportunity bits

In DS3 C-bit Parity Mode Only

1 Cb11 bit

1 Cb12 bit

1 Cb13 bit

3 Cb2 bits

3 Cb3 bits

3 Cb4 bits

3 Cb5 bits

3 Cb6 bits

3 Cb7 bits

Bit 171 for Application Identification Channel (AIC), set to 1

Bit 341 reserved, set to 1

Bit 511 for Far-End Alarm and Control (FEAC), bearing FEAC messages when active, set to 1 when inactive

Bits 851, 1021, and 1191 reserved, bearing a “111” pattern

Bits 1531, 1701, and 1871 for path parity, set to equal P-bits by terminating equipment (not to be modified by

path equipment)

Bits 2211, 2381, and 2551 for Far-End Block Error (FEBE), bearing a “111” pattern to signal error-free

conditions, any other to signal FEBE

Bits 2891, 3061, and 3231 for terminal data link (DL), bearing data link messages and flags when active, a

“111” pattern when inactive

Bits 3571, 3741, and 3911 reserved, bearing a “111” pattern

Bits 4251, 4421, and 4591 reserved, bearing a “111” pattern

28348-DSH-001-B

Mindspeed Technologies™

B-1

Share Link: