BT8376EPF datasheet(299/323 Pages) CONEXANT

299 / 323 page

N8370DSE

Conexant

A-1

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 Figure A-1 and Table A-1 and A-2.

The SF structure consists of a multiframe of 12 frames. Each frame has 24

channels, plus an F-bit, and 8 bits per channel. A channel is equivalent to one

voice circuit or one 64 kbps data circuit.

This structure of frames and multiframes is defined by the F-bit pattern. The

F-bit is designated alternately as an Ft bit (terminal framing bit) or an Fs bit

(signalling framing bit). The Ft bit carries a pattern of alternating 0s and 1s

(101010) in odd frames that defines the frame boundaries so that one channel can

be distinguished from another. The Fs bit carries a pattern of (001110) in even

frames, and defines the multiframe boundaries so that one frame can be

distinguished from another.

Figure A-1. T1 Superframe PCM Format

Frame 12

Frame 6

Bit 8

During:

24 Channels per Frame

Frame = 193 Bits

Multiframe

SF = 12 Frames

8 Bits per Channel

Signalling Information

BT8376EPF Datasheet(PDF) 299 Page - Synaptics Incorporated.