On-screen display controller ic, Overview functions overview functions – Sanyo EP58B User Manual

Page 30

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SANYO TV . VCR

SANYO TV . VCR

LC74785/M

SYNIN

RST

SEPOUT

SEPIN

XtalIN

CVIN CVOUT

OSCIN OSCOUT

DATA SLICER

CTRL1

(CHABLK)

XtalOUT

(MUTE)

COLR

SYNCJDG

VSS2

VDD2

VSS1

VDD1

LN21

CS2

CPDT

SCLK

SIN

CS1

LC74789/M/JM

SYNIN

SEPC

SEPOUT

SEPIN

OSCIN

OSCOUT

XtalIN

CVIN

CVCR

CVOUT

CTRL1

(CHABLK)

XtalOUT

(MUTE)

COLR

HFTONOUT

SYNCJDG

VSS2

VDD1

VDD2

VSS1

SCLK

RST

SIN

CS

Block Diagram

Block Diagram

Overview

Functions

Overview

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

On-Screen Display Controller IC

On-Screen Display Controller IC

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.

EDS support
Video input: NTSC composite video signal
Packages: LC74785: DIP24S (300mil)
LC74785M: MFP24 (375mil)

parallel

converter

Serial

8-bit latch

+

command

decoder

parallel

converter

Serial

8-bit latch

+

command

decoder

Data output

buffe

Output control

Horizontal

direction

character

size register

Vertical

direction

character

size register

Horizontal

display

position
register

Vertical

display

position
register

Blinking

and

inversion

control

register

Display

control

register

RAM
write

address

counter

Horizontal

size

counter

Vertical

size

counter

Horizontal

dot

counter

Vertical

dot

counter

Blinking

and

inversion

control

circuit

Decoder

Display RAM

Decoder

Horizontal

display

position

detection

Vertical

display

position

detection

Character

control

counter

Line

control

counter

Font ROM

DATA

peak hold

(slicer) circuit

HSYNC

peak hold

(slicer) circuit

Sync

discriminator

Pedestal clamp

Character
output dot

clock generator

Composite
sync signal

separator

control

Timing generator

Sync signal

generator

Character output control

Background control

Video output control

Shift register

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)

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.

Horizontal

direction

character

size register

Vertical

direction

character

size register

Horizontal

display

position
register

Vertical

display

position
register

Blinking

and

inversion

control register

Display

control

register

RAM write

address

counter

Horizontal

size counter

Vertical size

counter

Horizontal

dot counter

Vertical dot

counter

Blinking and

inversion

control circuit

Decoder

Decoder

Display RAM

Horizontal display
position detection

Vertical display

position detection

Character

control

counter

Line control

counter

Font ROM

Shift register

Character output control

Background control

Sync signal generator

Timing generator

Composite sync
signal separator

control

Character
output dot

clock

generator

Sync

discriminator

Sync

discriminator

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