Sanyo EP58B - Manual (Page 31)

LC74793/JM
59 60 SANYO TV . VCR SANYO TV . VCR
SYNCJDG CPOUT HOUT VOUT VCOIN XIN XOUT CTRL1 CDLR RST VCOR
VSS1,2
VDD1,2
CTRL2
SEPC
DAV
SCL
SDA
SEPIN
SYNIN
SEPOUT
LC74776/M
XtalIN CVIN CVOUT CTRL1
(CHABLK)
XtalOUT
(MUTE)
CVCR CDLR
SYNIN
SEPC
SEPOUT
OSCIN
OSCOUT
SYNCJDG
VDD1 VDD2 VDD3 VSS1 VSS2 VSS3
SCLK
SRT
SLC
SDA
VCOR
VCOIN
CPOUT
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: 256 characters (256 characters, one space character, one transparent space character)
Display start positions: Horizontal: 64 positions, vertical: 64 positions
Blinking: Specified in character 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
Blue background only: NTSC
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 input: PAL or NTSC composite video signal
Built-in PDC/VPS/UDT interface (I
2 C bus support)
Packages: LC74776: DIP30SD (400mil)
LC74776M: MFP30S (375mil)
On-Screen Display Controller IC
The LC74776 and LC74776M are integrated PDC/VPS/UDT interface circuit on-screen display CMOS ICs that display text and
patterns on the TV screen under control of a microcontroller.
The LC74776 and LC74776M display 12 18 dot characters in a display area of 12 lines by 24 columns.
Serial
parallel
converter
8-bit latch
+
command
decoder
Data output
buffer
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
AFC
circuit
Data slicer
circuit
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
Sync
discriminator
Character
output dot
clock
generator
Character
control
counter
Line control
counter Font ROM
Shift register
Character output control
Background control
Video output control
Sync signal generator Timing generator
Composite
sync signal
separator
control
Sync
separator
and data
separator
circuit
VPS data acquisition (bytes 5 and 11 to 15)
VPS: Video Program System
PDC (8/30/2) data acquisition (bytes 13 to 25)
PDC: Program Delivery Control
UDT (8/30/1) data acquisition (bytes 13 to 25)
UDT: Unified Date and Time
Header (X/00) data acquisition (bytes 14 to 45)
Status display (8/30/1, 8/30/2) data acquisition (bytes 26 to 45)
Automatic VPS/PDC discrimination mode
Sync separator and AFC circuits
Sync discrimination circuit
I
2 C bus support
Packages: LC74793: DIP24S (300mil)
LC74793JM: MFP24S (300mil)
VPS/PDC Slicer IC
The LC74793 and LC74793JM are PDC/VPS/UDT interface CMOS ICs. The operating mode can be set and the data acquired in the
various modes can be read out by a microcontroller.
I 2 C bus interface Data latch circuit
Sync separator
and data separator
circuits
Data acquisition circuit
Vertical
separation
circuit
Sync
discrimination
circuit
AFC circuit (VCO)
Timing generator