NEC DTE-29U1TH, Service Manual, Page: 20 / 71

-19-
Service Manual CP-785F
4-2 MSP341x Multistandard Sound Processor
The MSP341x is designed as a single-chip Multistandard Sound Processor for applications in
analogue and digital TV sets, video recorders, and PC cards.
MSP 341
x
features
- sound IF input
- No external filters required
- Stereo baseband input via integrated AD converters
- Two pairs of DA converters
- Two carrier FM or NICAM processing
- AVC : Automatic Volume Correction
- Bass, treble, volume processing
- Full SCART in/out matrix without restrictions
- Improved FM-identification
- Demodulator short programming
- Autodetection for terrestrial TV - sound standards
- Precise bit-error rate indication
- Automatic switching from NICAM to FM/AM or vice versa
- Improved NICAM synchronisation algorithm
- Improved carrier mute algorithm
- Improved AM-demodulation
- Reduction of necessary controlling
- Less external components
Basic Features of the MSP 341
x
Demodulator and NICAM Decoder Section
The MSP 341
x
is designed to simultaneously perform digital demodulation and decoding of
NICAM-
coded TV stereo sound, as well as demodulation of FM or AM mono TV sound. Alternatively,
two carrier FM systems according to the German terrestrial specs can be processed with the
MSP 341
x
.
The MSP 341
x
facilitates profitable multistandard capability, offering the following advantages:
- Automatic Gain Control (AGC) for analogue input: input range: 0.10 - 3 Vpp
- integrated A/D converter for sound-IF input
- all demodulation and filtering is performed on chip and is individually programmable
- easy realisation of all digital NICAM standards (B/G, I, L and D/K)
- FM-demodulation of all terrestrial standards (include identification decoding)
- no external filter hardware is required
- only one crystal clock (18.432 MHz) is necessary
- high deviation FM-mono mode (max. deviation: approx. –360 kHz)