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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
