CX28344 Conexant, CX28344 Datasheet - Page 189

• Manufacturer Part Number: CX28344
• Description: (CX2834x) Dual / Triple / Quad / Hex / Octal - Enhanced DS3 / E3 Framer
• Manufacturer: Conexant

Table B-1. Overhead Bits in DS3 Mode
28348-DSH-001-B
3 M-bits
28 F-bits
2 X-bits
2 P-bits
21 C-bits
7 stuff
opportunity bits
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
Field
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
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
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
Bits 597, 1278, 1959, 2640, 3321, 4002, and 4683
Appendix B: Frame Structure
\
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
As per ANSI T1.107-1995 and ITU-T G.704-1995, in DS3 mode, a frame is
Mindspeed Technologies™
In DS3 C-bit Parity Mode Only
In DS3 M13/M23 Mode Only
Table
Summary
Description
B-1.
B
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1