Toshiba 27WLT56B, Service Manual

Page: 22 / 84

19
27” TFT TV Service Manual 05/09/2005
12.15.
MSP34X1G
MSP3411G
Multistandard Sound Processor Family
12.15.1. Introduction
The MSP 34x1G 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 34x1G.
The MSP 34x1G has all functions of the MSP 34x0G with the addition of a virtual surround sound
feature.
Surround sound can be reproduced to a certain extent with two loudspeakers. The MSP 34x1G
includes the Micronas virtualizer algorithm “3D-PANORAMA” which has been approved by the Dolby
1)
Laboratories for with the "Virtual Dolby Surround" technology. In addition, the MSP 34x1G includes the
“PAN-ORAMA” algorithm.
These TV sound processing ICs include 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 34x1G has optimum stereo performance without any adjustments.
The MSP 34x1G has built-in automatic functions: The IC is able to detect the actual sound standard
automat-ically (Automatic Standard Detection). Furthermore, pilot levels and identification signals can
be evaluated internally with subsequent switching between mono/stereo/bilingual; no I
2
C interaction is
necessary (Automatic Sound Selection).
Source Select
I
2
S bus interface consists of five pins:
1. I
2
S_DA_IN1, I2S_DA_IN2: For input, four channels (two channels per line, 2*16 bits) per sampling
cycle (32 kHz) are transmitted.
2. I
2
S _DA_OUT: For output, two channels (2*16 bits) per sampling cycle (32 kHz) are transmitted.
3. I
2
S _CL: Gives the timing for the transmission of I
2
S serial data (1.024 MHz).
4. I
2
S _WS: The I
2
S _WS word strobe line defines the left and right sample.