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Pop tuner, Outline of channel selection circuit system – Toshiba TW40F80 User Manual

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POP and Double Window signal processing (QY03), IC for

closed caption control (QM01), IC for WAC control (QX01),

IC for 3D-YCS (QZ01), IC for AUTOLIVE (QK06).

Differences from N5SS chassis are as follows;

1. On-screen function inside microcomputer is used. Sepa-

rate IC is not used for on-screen.

2. The microcomputer does not have the closed caption

function, but controls separate IC for closed caption.

3. The system uses two channels of I

2

C bus. One is only

for non-volatile memory.

1. OUTLINE OF CHANNEL SELECTION CIRCUIT SYSTEM

The channel selection circuit in the N5SS chassis employs

a bus system which performs a central control by connect-

ing a channel selection microcomputer to a control IC in

each circuit block through control lines called a bus. In the

bus system which controls each IC, the I

2

C bus system (two

line bus system) developed by Philips Co. Ltd. in the Neth-

erlands has been employed.

The ICs controlled by the I

2

C bus system are: IC for V/C/D

signal processing (Q501), IC for A/V switching (QV01), IC for

non volatile memory (QA02), Main and sub U/V tuners (H001,

HY01), IC for deflection distortion correction (Q302), IC for

Toshiba made 8 bit microcomputer TLCS-870 series for TV

receiver, TMP87CS38N-3320 is employed for QA01.

With this microcomputer, each IC and circuit shown below

are controlled.

(1)

CONTROL OF VIDEO/CHROMA/DEF SIGNAL

PROCESS IC (Q501 Toshiba TA1222AN)

Adjustments for uni-color, brightness, tint, color

gain, sharpness and PIP uni-color

Setting of adjustment memory values for sub-

brightness, sub-color and sub-tint, etc.

Setting of memory values for video parameters such

as white balance (RGB cutoff, GB drive) and

g

correction, etc.

Setting of video parameters of video modes (Stan-

dard, Movie, Memory)

(2)

CONTROL OF A/V SWITCH IC (QV01 Toshiba

TA1218N)

Performs source switching for main screen and sub

screen

Performs source switching for TV and three video

inputs

(3)

CONTROL OF NON-VOLATILE MEMORY IC

(QA02 Microchip 24LC08BI/P)

Memorizes data for video and audio signal adjust-

ment values, volume and woofer adjustment val-

ues, external input status, etc.

Memorizes adjustment data for white balance (RGB

cutoff, GB drive), sub-brightness, sub color, sub

tint, etc.

Memorizes deflection distortion correction value

data adjusted for each unit.

SECTION III: CHANNEL SELECTION CIRCUIT

2. OPERATION OF CHANNEL SELECTION CIRCUIT

(4)

CONTROL OF U/V TUNER UNIT (H001 Toshiba

ELA12L, HY01 Toshiba EL922L)

A desired channel can be tuned by transferring a

channel selection frequency data (divided ratio data)

to the I

2

C bus type frequency synthesizer equipped

in the tuner, and by setting a band switch data which

selects the UHF or VHF band.

(5)

CONTROL OF DEFLECTION DISTORTION COR-

RECTION IC (Q302 Toshiba TA8859P)

Sets adjustment memory value for vertical ampli-

tude, linearity, horizontal amplitude, parabola, cor-

ner, trapezoid distortion.

(6)

CONTROL OF POP & Double Window SIGNAL PRO-

CESS IC (QY03 Toshiba TC9092AF, QY91 Sony

CXP85116B-514Q)

Controls ON/OFF and 9 pictures serch of POP.

(7)

CONTROL OF CLOSED CAPTION/EDS (QM01

Motorola XC144144P)

Controls Closed Caption/EDS.

(8)

CONTROL OF WAC (QX01 Toshiba TC9097F)

Controls Wide Aspect.

(9)

CONTROL OF 3D-YCS (QZ01 Toshiba TC9086F)

Controls ON/OFF of 3 Dimension Y/C separator.

(10) CONTROL OF VERTICAL AMPLITUDE (QK06

Toshiba TMP87CM36N)

Controls Wide Mode.

(11) CONTROL OF OSD (Do not I

2

C BUS) (QR60 Fujitsu

MB90091)

Controls of OSD Menu.