On-Screen Display Controller Ic - Sanyo EP58B Catalogue

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.
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
Serial
CS1 8-bit latch
+
SIN
parallel
command
SCLK converter decoder
Horizontal
direction
character
Data output
size register
CPDT Output control
buffe
CS2 Horizontal
size
LN21 DATA SLICER
counter
V DD 1
V SS 1
V DD 2
V SS 2
Sync
SYNCJDG
discriminator
DATA HSYNC
Composite
peak hold peak hold
sync signal
(slicer) circuit (slicer) circuit
separator
control
Pedestal clamp
Character
output dot
clock generator
SYN IN RST SEP OUT OSC IN OSC OUT SEP IN
57
SANYO TV . VCR
EDS support
Video input: NTSC composite video signal
Packages: LC74785: DIP24S (300mil)
LC74785M: MFP24 (375mil)
Block Diagram
Vertical Horizontal Vertical RAM
Blinking
Display
and
direction display display write
control
inversion
character position position address
control
register
size register register register counter
register
Vertical Horizontal Vertical Blinking
size dot dot and
Display RAM
counter inversion
counter counter
control
circuit
Horizontal Vertical
display
display
position
position
detection detection
Decoder
Character Line
control control
counter counter
Font ROM
Character output control
Sync signal
Shift register
Timing generator Background control
generator
Video output control
Xtal IN COLR CV IN CV OUT
CTRL1 Xtal OUT
(CHABLK) (MUTE)
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 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
CS
Serial
8-bit latch
SIN +
parallel command
decoder
converter
SCLK
Horizontal Vertical Horizontal
direction direction
RST
character character position
size register size register
V DD 1
Horizontal Vertical size Horizontal
V SS 1
size counter
counter dot counter
V DD 2
Horizontal display
position detection
V SS 2
Sync
Character
SYNC JDG
discriminator
Character
OSC IN
output dot
clock
generator
OSC OUT
Timing generator
SYN IN
Composite sync
Sync
SEP C
signal separator
discriminator
control
SEP OUT
SEP IN
Vertical
Blinking
RAM write
Display
display display
and
control address
position inversion
register
counter
register register control register
Blinking and
Vertical dot
inversion
Display RAM
counter
control circuit
Vertical display
position detection
Decoder
Line control
control
counter
Font ROM
counter
Character output control
Sync signal generator
Shift register
Background control
Xtal IN Xtal OUT HFTON OUT CV CR CV OUT
CTRL1
(MUTE)
(CHABLK) COLR CV IN
SANYO TV . VCR
58