cx28394 Conexant Systems, Inc., cx28394 Datasheet - Page 279

• Manufacturer Part Number: cx28394
• Description: Quad/x16/octal-t1/e1/j1 Framers
• Manufacturer: Conexant Systems, Inc.

Figure A-1. T1 Superframe PCM Format
100054E
Fs
Ft
or
CH
FR
1
1
1
CH
2
FR
2
2
8 Bits per Channel
Appendix A
A.1 Superframe Format (SF)
The Superframe Format (SF), is also referred to as the D4 format. The
requirement for associated signaling in frames 6 and 12 dictates that the frames
be distinguishable. This leads to a multiframe structure consisting of 12 frames
per superframe (SF). See
channels, plus an F-bit, and 8 bits per channel. A channel is equivalent to one
voice circuit or one 64 kbps data circuit.
F-bit is designated alternately as an Ft bit (terminal framing bit) or Fs bit
(signalling framing bit). The Ft bit carries a pattern of alternating zeros and ones
(101010) in odd frames that defines the frame boundaries so that one channel
may be distinguished from another. The Fs bit carries a pattern of (001110) in
even frames and defines the multiframe boundaries so that one frame may be
distinguished from another.
The SF structure consists of a multiframe of 12 frames. Each frame has 24
This structure of frames and multiframes is defined by the F-bit pattern. The
3
4
CH
13
FR
7
Conexant
5
Figure A-1
6
A
and
7
Tables A-1
FR
11
Signaling Information
8
FR
CH
12
A
24
B
and A-2.
24 Channels per Frame
SF = 12 Frames
Frame = 193 Bits
Multiframe
Bit 8
During:
Frame 12
Frame 6
A-1