Panasonic KX-F1200 Service Manual And Technical Manual page 140

KX-Fi200 (
12. DIGITAL TAM SECTION
• DSP (Digital Speech/Signal Processing) Circuit
General Description:
IC701~1C703 is a digital speech/signal processing system that implements all the functions of speech compression, record and
playback, and memory management required in a digital telephone answering machine.
The DSP system is fully controlled by a host processor (IC401), via 8 bit interface. The host processor provides activation and
control of all that functions, such as speech Recording, Playback, Tone detecting and Line Monitoring.
The DSP system comprises of following:
The Digital Signal Processor which includes the firmware implemented functions.
The Codec (IC702), which is used as the analog I/O interface.
The Audio grade RAM (IC703), which is used for stored voice messages.
................................................................... .
1+
Host i
Processor
(IC401)
DSP
(IC701)
Analog I/O -_ i
(IC702) I i
ARAM I
(IC703)
Audio In
..--"-- Audio Out
Digital TAM Unit
Voice Message Recording:
The DSP system use a proprietary speech compression techniqueto record and store voice message in audio grade RAMs (IC703,
IC704).
An error correctionalgorithmis used to enableplaybackof these messagesfromthe ARAM.
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