CT8022 Datasheet, PDF (189/194 Pages) List of Unclassifed Manufacturers – VOIP/VON G.723.1, G279AB TRUESPEECH CO-PROCESSOR

Version: 1.18
PRELIMINARY/CONFIDENTIAL
TrueSpeech® Co-Processor
E G.723.1 Frame Structure
This appendix shows the bit packing scheme used for compressed speech blocks for the G.723.1 6.3 and 5.3 bit
rates. Note that the bit packing arrangement has changed from that used by the (pre-release) v3.0 of G.723.1, which
was incorporated into the original CT8020A11AQC engineering samples and v4.0 in the CT8020A11BQC devices.
The following shows the bit packing used by all versions of the CT8022 and the CT8020D11AQC for the 6.3 data
rate. The compressed speech frame consists of a block of 12 16-bit words. The least significant 2 bits indicate the
type of compressed speech block.
LSP Index ( low 14 bits )
(15-2)
Vad + Rate
(1-0)
Adapt. CodeBook Lag_0:6bits
(15-10)
LSP Index : (high 10 bits)
(9-0)
Combined_Gain_0 Adapt.CdBkLag_3
(15-12)
(11-10)
Adapt.CodeBookLag_2:7bits
(9-3)
Adapt.CdBkLag_1 Adapt.CdBk Lag:_0
(2-1)
(0)
Combined_Gain_1:8bits
(15-8)
Combined_Gain_0:8bits
(7-0)
Combined_Gain_2:12bits
(15-4)
Combined_Gain_1:4bits
(3-0)
Grid_3 Grid_2 Grid_1 Grid_0
(15) (14) (13) (12)
Combined_Gain_3:12bits
11-0)
Pulse_Position_0:2bits
(15-14)
Combined_Position_Index:13bits
(13-1)
Reserved Bit
(0)
Pulse_Position_1:2bits
(15-14)
Pulse_Position_0:14bits
(13-0)
Pulse_Position_2:4bits
(15-12)
Pulse_Position_1:12bits
(11-0
Pulse_Position_3:4bits
(15-12)
Pulse_Position_2:12bits
(11-0)
Pulse_Sign_0:6bits
Pulse_Position_3:10bits
(15-10)
(9-0)
CT8022A11AQC FW Revision 0118
DSP GROUP, INC., 3120 SCOTT BOULEVARD
189
SANTA CLARA, CA 95054 PH: 408 986 – 4300 FAX: 408 986 – 4490
All specifications are subject to change without prior notice.