Hitachi 22LD4500UK, Руководство по обслуживанию

Страница: 28 / 59

25
11.20. MSP34X0G
MSP3400G
Multistandard Sound Processor Family
11.20.1. Introduction
The MSP 34x0G family of single-chip Multistandard Sound Processors covers the sound processing of all
analog TV-Standards worldwide, as well as the NICAM digital sound standards. The full TV sound
processing, starting with analog sound IF signal-in, down to processed analog AF-out, is performed on a
single chip. Figure shows a simplified functional block diagram of the MSP 34x0G.
This new generation of TV sound processing ICs now includes versions for processing the multichannel
television sound (MTS) signal conforming to the standard recommended by the Broadcast Television
Systems Committee (BTSC). The DBX noise reduction, or alternatively, MICRONAS Noise Reduction
(MNR) is performed alignment free. Other processed standards are the Japanese FM-FM multiplex
standard (EIA-J) and the FM Stereo Radio standard. Current ICs have to perform adjustment procedures
in order to achieve good stereo separation for BTSC and EIA-J. The MSP 34x0G has optimum stereo
performance without any adjustments.
All MSP 34x0G versions are pin and software downward compatible to the MSP 34x0D. The MSP 34x0G
further simplifies controlling software. Standard selection requires a single I²C transmission only.
The MSP 34x0G has built-in automatic functions: The IC is able to detect the actual sound standard
automatically (Automatic Standard Detection). Furthermore, pilot levels and identification signals can be
evaluated internally with subsequent switching between mono/stereo/bilingual; no I²C interaction is
necessary (Automatic Sound Selection).
Source Select
I
2
S bus interface consists of five pins:
1. I2S_DA_IN1, I2S_DA_IN2: For input, four channels (two channels per line, 2*16 bits) per sampling cycle
(32 kHz) are transmitted.
2. I2S_DA_OUT: For output, two channels (2*16 bits) per sampling cycle (32 kHz) are transmitted.
3. I2S_CL: Gives the timing for the transmission of I
2
S serial data (1.024 MHz).
4. I2S_WS: The I2S_WS word strobe line defines the left and right sample.
11.20.2. Features
• Standard Selection with single I
2
C transmission
• Automatic Standard Detection of terrestrial TV standards
• Automatic Sound Selection (mono/stereo/bilingual), new registers MODUS, STATUS
• Two selectable sound IF (SIF) inputs
• Automatic Carrier Mute function
• Interrupt output programmable (indicating status change)
• Loudspeaker / Headphone channel with volume, balance, bass, treble, loudness
• AVC: Automatic Volume Correction
• Subwoofer output with programmable low-pass and complementary high-pass filter