CT8022 Datasheet, PDF (124/194 Pages) List of Unclassifed Manufacturers – VOIP/VON G.723.1, G279AB TRUESPEECH CO-PROCESSOR

TrueSpeech® Co-Processor
PRELIMINARY/CONFIDENTIAL
Version: 1.18
9.19.2 Synchronous Mode
In this mode (default), the duration of the tone is determined by the number of frame periods for which the command
is repeated. Synchronous mode is the default mode and is compatible with the tone generation of the CT8005
TrueSpeech Messaging Co-Processor.
The CT8022 creates the output waveform in frames of 30ms each (240 samples at 8.0 KHz). The CT8022 will
check for a Host command at the end of each frame after updating the status response and asserting Status Ready in
the Hardware Status Register. If the Host repeats the original command, the status reply is repeated, and tone
generation is continuous. If the Host changes the tone parameters, the waveform output is changed accordingly. If
the command is the Idle command, tone generation is terminated. Note that the CT8022 requires that the Idle
command be used to correctly terminate tone generation. If the Host does not issue any command, the CT8022
continues to check for a command every 30ms and continues to generate the tone specified by the last command.
To generate a tone of 90ms duration in this mode, the Host performs the following sequence:
1. Write tone command 60XXH.
2. Wait for Status Ready (30ms delay).
3. Repeat tone command.
4. Wait for Status Ready.(30ms delay).
5. Repeat tone command.
6. Wait for Status Ready.(30ms delay).
7. Write idle command (0000H).
To generate a silence gap of 90ms, use the above sequence with the tone command 6000H. This generates a special
silence tone.
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DSP GROUP, INC., 3120 SCOTT BOULEVARD
CT8022A11AQC FW Revision 0118
SANTA CLARA, CA 95054 PH: 408 986 – 4300 FAX: 408 986 – 4490
All specifications are subject to change without prior notice.