On-Screen Display Controller IC

LC74785/M

Overview

The LC74785 and LC74785M are integrated EDS on-screen display CMOS ICs that display text and patterns on the TV screen under control of a microcontroller. The LC74785 and LC74785M display 12 18 dot characters in a display area of 12 lines by 24 columns.

On-Screen Display Controller IC

LC74789/M/JM

Overview

The LC74789, LC74789M, and LC74789JM are on-screen display CMOS ICs that display text and patterns on the TV screen under control of a microcontroller. The LC74789, LC74789M, and LC74789JM display 12 18 dot characters in a display area of 12 lines by 24 columns.

Functions

Display structure: 12 lines 24 characters (up to 288 characters)

Character structure: 12 18 dots (H V)

Character sizes: Three sizes in each of the horizontal and vertical directions

Number of characters: 128 characters

Display start positions: Horizontal: 64 positions, vertical: 64 positions

Blinking: Specified in horizontal units

Types of blinking: Two: periods of 1.0 and 0.5 seconds

Blinking of the whole character area (12 18 dots)

Background color: 8 colors (internal synchronization operation) at 4 fsc 6 colors (internal synchronization operation) at 2 fsc

Line background color: Can be set for up to 3 lines

Line background color: 8 colors (internal synchronization operation) at 4 fsc

Line background color: 6 colors (internal synchronization operation) at 2 fsc External control input: 8-bit serial interface

Built-in sync separator circuit

EDS support

Video input: NTSC composite video signal Packages: LC74785: DIP24S (300mil)

LC74785M: MFP24 (375mil)

Functions

Display structure: 12 lines 24 characters (up to 288 characters)

Character structure: 12 18 dots (H V)

Character size: Three sizes in each of the horizontal and vertical directions

Number of characters: 256 characters (254 characters, one space character, one transparent space character)

Display start positions: Horizontal: 64 positions, vertical: 64 positions

Blinking: Specified in horizontal units

Types of blinking: Two: periods of 1.0 and 0.5 seconds

Blinking of the whole character area (12 18 dots)

Background color: 8 colors (internal synchronization operation) at both 2 and 4 fsc

Line background color: Can be set for up to 3 lines

Line background color: 8 colors (internal synchronization operation) at both 2 and 4 fsc External control input: 8-bit serial interface

Built-in sync separator circuit

Video signal inputs: NTSC, PAL, PAL-N, PAL-M, NTSC 4.43, and PAL60 composite video signals Packages: LC74789: DIP24S (300mil), LC74789M: MFP24 (375mil), LC74789JM: MFP24S (300mil)

Block Diagram

Block Diagram

CS1

SIN

SCLK

CPDT

CS2

LN21

Data output

buffe

Serial

8-bit latch

 

 

 

 

 

 

 

parallel

+

 

 

 

 

 

 

 

command

 

 

 

 

 

 

 

converter

decoder

Horizontal

Vertical

Horizontal

Vertical

Blinking

Display

RAM

 

 

direction

direction

display

display

and

write

 

 

inversion

control

 

 

character

character

position

position

address

 

 

control

register

Output control

 

size register

size register

register

register

register

counter

 

 

 

 

 

Horizontal

 

 

Vertical

 

Horizontal

 

Vertical

 

Blinking

 

 

 

 

Decoder

 

 

 

DATA SLICER

 

size

 

 

 

 

size

 

 

dot

 

dot

 

and

 

 

 

 

 

 

 

Display RAM

 

counter

 

 

counter

 

counter

 

counter

 

inversion

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

control

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

circuit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CS

Serial

8-bit latch

 

 

 

 

 

 

 

 

 

 

 

 

 

SIN

parallel

+

 

 

 

 

 

 

 

command

 

 

 

 

 

 

SCLK

converter

decoder

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Horizontal

Vertical

Horizontal

Vertical

Blinking

Display

RAM write

 

 

direction

direction

display

display

and

RST

 

control

address

 

character

character

position

position

inversion

 

 

register

counter

 

 

size register

size register

register

register

control register

VDD1

 

 

 

 

 

 

 

 

 

Horizontal

 

Vertical size

 

Horizontal

 

Vertical dot

Blinking and

 

Decoder

 

 

VSS1

size counter

 

counter

 

dot counter

 

counter

inversion

 

 

Display RAM

 

 

 

 

 

 

 

 

 

 

control circuit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VDD1

VSS1

VDD2

VSS2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SYNCJDG

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sync

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

discriminator

 

 

 

DATA

 

 

 

 

HSYNC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

peak hold

 

 

peak hold

 

 

 

 

 

 

Composite

 

 

 

 

 

 

 

 

 

 

 

sync signal

 

 

 

 

(slicer) circuit

 

 

(slicer) circuit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

separator

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

control

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pedestal clamp

 

 

 

 

 

 

 

 

Character

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

output dot

 

 

 

 

 

 

 

 

 

 

 

 

 

 

clock generator

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Horizontal

Vertical

display

display

position

position

detection

detection

Character

Line

control

control

counter

counter

Timing generator

 

 

 

Sync signal

 

Character output control

 

 

 

 

 

 

 

Background control

 

 

 

generator

 

 

 

 

 

 

Video output control

 

 

 

 

 

 

Decoder

Font ROM

Shift register

VDD2

 

Horizontal display

Vertical display

 

 

VSS2

 

position detection

position detection

 

Decoder

 

 

 

 

SYNCJDG

Sync

Character

Line control

 

 

discriminator

control

 

 

 

 

counter

counter

 

Font ROM

 

 

 

 

OSCIN

Character

 

 

 

 

 

 

 

 

output dot

 

 

 

 

 

clock

 

 

 

 

OSCOUT

generator

 

 

Character output control

 

 

Timing generator

Sync signal generator

Shift register

 

Background control

 

 

 

 

 

SYNIN

Sync

Composite sync

SEPC

signal separator

discriminator

SEPOUT

control

 

SEPIN

 

 

 

 

 

XtalIN

COLR CVIN CVOUT

SYNIN

RST SEPOUT OSCIN OSCOUT SEPIN

 

 

CTRL1

XtalOUT

 

 

(CHABLK)

(MUTE)

CTRL1

XtalIN XtalOUT

HFTONOUT

CVCR CVOUT

(CHABLK)

(MUTE)

COLR

CVIN

57 SANYO TV . VCR

SANYO TV . VCR 58

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Sanyo EP58B specifications LC74785/M, LC74789/M/JM