SANYO LC74785M

Ordering number : EN5520A
CMOS LSI
LC74785, LC74785M
On-Screen Display Controller LSI
Overview
Package Dimensions
The LC74785 and LC74785M are on-chip EDS CMOS
LSIs for on-screen display, a function that displays
characters and patterns on a TV screen under
microprocessor control. These LSIs support 12 × 18 dot
characters and can display 12 lines by 24 characters of
text.
unit: mm
3067-DIP24S
[LC74785]
Features
• Display format: 24 characters by 12 rows (Up to 288
characters)
• Character format: 12 (horizontal) × 18 (vertical) dots
• Character sizes: Three sizes each in the horizontal and
vertical directions
• Characters in font: 128
• Initial display positions: 64 horizontal positions and 64
vertical positions
• Blinking: Specifiable in character units
• Blinking types: Two periods supported: About 1.0
second and about 0.5 second
• Blanking: Over the whole font (12 × 18 dots)
• Background color
— Background coloring: 8 colors (internal synchronization
mode): 4fsc
— Background coloring: 6 colors (internal synchronization
mode): 2fsc
• Line background color
— Can be set for 3 lines
— Line background coloring: 8 colors (internal synchronization mode): 4fsc
— Line background coloring: 6 colors (internal synchronization mode): 2fsc
• External control input: 8-bit serial input format
• On-chip sync separator circuit
• EDS support
• Video output
— NTSC-format composite output
• Package
24-pin plastic DIP (300 mil)
24-pin plastic SOP (375 mil)
SANYO: DIP24S
unit: mm
3045B-MFP24
[LC74785M]
SANYO: MFP24
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
63097HA (OT) No. 5520-1/24
LC74785, LC74785M
Pin Assignment
Pin Functions
Pin No.
Pin
Function
1
VSS1
Ground
2
Xtal IN
3
4
5
Notes
Ground connection (digital system ground)
Crystal oscillator
(MUTE input)
These pins are used either to connect the crystal and capacitor used to form an
external crystal oscillator used to generate the internal synchronizing signals, or
to input an external clock signal (2fsc or 4fsc). As a mask option, the Xtalout pin
can be set to function as the MUTE input pin. When this pin is set low, the video
output is held at the pedestal level. (A pull-up resistor is built in and the input has
hysteresis characteristics.)
(CHABLK)
Crystal oscillator input switching
(CHABLK output)
Switches the mode between external clock input and crystal oscillator operation.
A low level selects crystal oscillator operation and a high level selects external
clock input. As a mask option, the CTRL1 input pin can be set to function as the
CHABLK (character border) output. This is a 3-value output.
LN21
Data output
Line 21H pulse output
(Even fields when MOD1 is low, both fields when MOD1 is high)
LC oscillator
Connections for the coil and capacitor that form the character output dot clock
generation oscillator.
Xtal OUT
(MUTE)
CTRL1
6
OSC IN
7
OSC OUT
Outputs the state of the external synchronizing signal presence/absence judgment. Outputs a
high level when synchronizing signals are present.
Outputs a field discrimination pulse (O/E pulse) when SEL2 is high.(HLFTON: Valid when 0)
HLFTON: A signal in the range specified by LNA*, LNB*, and LNC* is output when HLFTON is
high.)
Outputs the dot clock (LC oscillator) when CS1 is high and RST is low. (This signal is not
output on command resets.)
Outputs the crystal oscillator clock when CS1 is low and RST is low. (This signal is not output
on command resets.)
8
SYNC JDG
External synchronizing signal judgment output
9
CS1
Enable input
Enable input pin for the OSD serial data input function.
Serial data input is enabled when this pin is low.
A pull-up resistor is built in. (The input has hysteresis characteristics.)
10
SCLK
Clock input
Input for the serial data input clock.
A pull-up resistor is built in. (The input has hysteresis characteristics.)
11
SIN
Data input
Serial data input. A pull-up resistor is built in. (The input has hysteresis
characteristics.)
12
VDD2
Power supply
13
CVOUT
Video signal output
14
VSS2
Ground
Composite video signal level adjustment power supply (analog system power
supply)
Composite video signal output
Ground connection (analog system ground)
Continued on next page.
No. 5520-2/24
LC74785, LC74785M
Continued from preceding page.
Pin No.
Pin
Function
15
CV IN
Video signal input
Notes
Composite video signal input
16
VDD1
Power supply
17
SYNIN
Sync separator circuit input
18
CDLR
Background color phase adjustment
Background color phase adjustment. Connect to ground through a resistor and a capacitor.
19
SEPOUT
Composite synchronizing signal output
Video signal output for the built-in sync separator circuit. Can be switched to function
as an output for signal (high or ST. pulse) due to MOD0 by setting SEL0 high.
Vertical synchronizing signal input
Inputs the vertical synchronizing signal created by integrating the SEPOUT pin output
signal.
An integration circuit must be connected to the SEPOUT pin. This pin must be tied to
VDD1 if unused. This pin can be switched to function as the frame signal input mode
by setting SEL1 high. (This is valid when CTL3 is set to 1.)
20
SEP
IN
Power supply (+5 V: digital system power supply)
Video signal input for the built-in sync separator circuit
21
CS2
Enable input
EDS data output enable input. EDS data output is enabled when this pin is low. A
pull-up resistor is built in. (The input has hysteresis characteristics.)
22
CPDT
Data output
EDS data output (This pin can be either an n-channel open-drain output or a CMOS
output.)
23
RST
Reset input
System reset input
A pull-up resistor is built in. (The input has hysteresis characteristics.)
24
VDD1
Power supply (+5 V)
Power supply (+5 V: digital system power supply)
Note: Both VDD1 pins must be connected to the power supply.
Specifications
Absolute Maximum Ratings at Ta = 25°C
Parameter
Symbol
Conditions
Ratings
Unit
Supply voltage
VDD
VDD1 and VDD2
VSS–0.3 to VSS+7.0
V
Input voltage
VIN
All input pins
VSS–0.3 to VDD+0.3
V
LN21, CPDT, SEPOUT, and SYNCJDG
VSS–0.3 to VDD+0.3
Output voltage
VOUT
Allowable power dissipation
Pd max
Ta = 25°C
V
350
mW
Operating temperature
Topr
–30 to +70
°C
Storage temperature
Tstg
–40 to +125
°C
Allowable Operating Ranges at Ta = –30 to +70°C
Parameter
Supply voltage
Input high-level voltage
Input low-level voltage
Pull-up resistance
Composite video signal input voltage
Input voltage
Oscillator frequency
Symbol
Conditions
Ratings
min
typ
Unit
max
VDD1
VDD1
4.5
5.0
5.5
V
VDD2
VDD2
4.5
5.0
1.27VDD1
V
VIH1
RST, CS1, CS2, SIN, SCLK, SEPIN,
and MUTE
0.8VDD1
VDD1 + 0.3
V
VIH2
CTRL1
0.7VDD1
VDD1 + 0.3
V
VIL1
RST, CS1, CS2, SIN, SCLK, SEPIN,
and MUTE
VSS – 0.3
0.2VDD1
V
VIL2
CTRL1
VSS – 0.3
0.3VDD1
V
RPU
Applies to pins set for the RST, CS1, CS2,
SIN, SCLK, and MUTE pin options.
VIN1
CVIN; VDD1 = 5 V
VIN2
SYNIN; VDD1 = 5 V
VIN3
XtalIN (When external clock input is used)
fin = 2 fsc or 4 fsc ; VDD1 = 5 V
25
50
90
2.0
1.5
2.0
0.10
kΩ
Vp-p
2.5
Vp-p
5.0
Vp-p
FOSC1
The XtalIN and XtalOUT oscillator pins
(2 fsc: NTSC)
7.159
MHz
FOSC1
The XtalIN and XtalOUT oscillator pins
(4 fsc: NTSC)
14.318
MHz
FOSC2
The OSCIN and OSCOUT oscillator pins
(LC oscillator)
5
10
MHz
Note: When the XtalIN pin is used in clock input mode, extreme care must be taken to prevent noise from entering the input signal.
No. 5520-3/24
LC74785, LC74785M
Electrical Characteristics at Ta = –30 to +70°C, VDD1 = 5 V unless otherwise specified.
Parameter
Symbol
Ratings
Conditions
min
typ
Unit
max
Input off leakage current
Ileak1
CVIN
1
µA
Output off leakage current
Ileak2
CVOUT
1
µA
Output high-level voltage
VOH1
LN21, SYNCJDG, CPDT, and SEPOUT;
VDD1 = 4.5 V, IOH = –1.0 mA
Output low-level voltage
VOL1
LN21, SYNCJDG, CPDT, and SEPOUT;
VDD1 = 4.5 V, IOL = 1.0 mA
CHABLK; VDD1 = 5.0 V
Three-value output voltage
Input current
Operating mode current drain
VO
3.5
V
1.0
V
H
3.3
5.0
V
M
1.8
2.3
V
L
0
0.8
V
1
µA
IIH
RST, CS1, CS2, SIN, SCLK, CTRL1,
SEPIN, and MUTE; VIN = VDD1
IIL
CTRL1 and OSCIN; VIN = VSS1
IDD1
VDD1; All outputs open, Xtal: 7.159 MHz,
LC: 8 MHz
IDD2
VDD2: VDD2 = 5 V
–1
µA
30
mA
20
mA
SYNC level
VSN
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
Pedestal level
VPD
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
1.32
1.52
1.81
1.44
1.64
1.93
1.56
1.76
2.05
V
V
V
Color burst low level
VCBL
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
0.98
1.17
1.46
1.10
1.29
1.58
1.22
1.41
1.70
V
V
V
Color burst high level
VCBH
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
1.63
1.83
2.11
1.75
1.95
2.23
1.87
2.07
2.35
V
V
V
Background color other than blue low level
VRSL0
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
1.17
1.36
1.65
1.29
1.48
1.77
1.41
1.60
1.89
V
V
V
Background color other than blue high level
VRSH0
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
2.33
2.52
2.81
2.45
2.64
2.93
2.57
2.76
3.05
V
V
V
Blue background color 1low level
VRSL1
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
1.08
1.27
1.56
1.20
1.39
1.68
1.32
1.51
1.80
V
V
V
Blue background color 2 low level
VRSL2
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
1.49
1.68
1.97
1.61
1.80
2.09
1.83
1.92
2.21
V
V
V
Blue background color 1, 2 high level
VRSH1
VRSH2
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
1.97
2.17
2.46
2.09
2.29
2.58
2.21
2.41
2.70
V
V
V
Frame level 0
VBK0
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
1.40
1.60
1.89
1.52
1.72
2.01
1.64
1.84
2.13
V
V
V
Frame level 1
VBK1
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
1.97
2.17
2.46
2.09
2.29
2.58
2.21
2.41
2.70
V
V
V
Character level
VCHA
CVOUT; VDD1 = 5.0 V, VDD2 = 5.0 V
*1
*2
*3
2.55
2.75
3.04
2.67
2.87
3.16
2.79
2.99
3.28
V
V
V
Note: 1.
2.
3.
0.70
0.89
1.18
0.82
1.01
1.30
0.94
1.13
1.42
V
V
V
When the sync level is 0.8 V
When the sync level is 1.0 V
When the sync level is 1.3 V
No. 5520-4/24
LC74785, LC74785M
Timing Characteristics at Ta = –30 to +70°C, VDD1 = 5 ±0.5 V
OSD write (See Figure 1.)
Parameter
Minimum input pulse width
Data setup time
Data hold time
One word write time
Symbol
Ratings
Conditions
min
tW(SCLK)
SCLK
tW(CS1)
CS1 (The period when CS1 is high)
tSU(CS1)
tSU(SIN)
typ
max
Unit
200
ns
1
µs
CS1
200
ns
SIN
200
ns
th(CS1)
CS1
2
µs
th(SIN)
SIN
200
ns
tword
The time to write 8 bits of data
4.2
µs
1
µs
The RAM data write time
twt
EDS read (For the n-channel open-drain circuit, see Figure 2.)
Parameter
Symbol
Ratings
Conditions
min
typ
max
Unit
tCKCY
SCLK
2
µs
tCKL
SCLK
1
µs
tCKH
SCLK
1
µs
Setup time
tICK
SCLK
10
µs
Output delay time
tCKO
CPDT
Minimum input pulse width
0.5
µs
Note: The CMOS output circuit follows the OSD timing.
First byte
Second byte
Figure 1 OSD Serial Data Input Timing
Note: CPDT goes to the high-impedance state when CS2 is high.
Figure 2 EDS Serial Output Test Conditions (For the n-channel open-drain circuit.)
No. 5520-5/24
(Line number)
(Line number)
Note:
The O/E signal is output from the SYNCJDG pin when SEL2 is high.
LN21 is output for even fields when MOD1 is low and for both fields when MOD1 is high.
Even field
Odd field
Pulse output when MOD1 is low or high
Pulse output when MOD1 is high
LC74785, LC74785M
Figure 3 O/E and LN21 Output Timing
No. 5520-6/24
The previous data is output.
The 16 bits of caption data is output LSB first
in synchronization with SCLK falling edges.
High-impedance
Note: When extracting closed caption character data when MOD1 is high (NTSC-TV), applications must determine whether the current field is odd or
even by checking the signal level output from the SYNCJDG pin (with SEL2 set high) when a falling edge is detected on LN21.
High-impedance
CS2 is switched from high to low after the decoder LSI (microcontroller) detects a falling edge on LN21.
Caption data is transferred to the data output buffer.
A pulse is output at line 21 in even fields when MOD1 is low.
A pulse is output at line 21 in both fields when MOD1 is High.
LC74785, LC74785M
Figure 4 Transferring caption data from the LC74785/M to the decoder LSI (microcontroller): Method 1
(Basic LC74785/M usage)
No. 5520-7/24
LC74785, LC74785M
The timing of the transfer of caption data to the data output buffer is synchronized with the falling edge of the pulse
output from LN21. Therefore, the software processing shown below is required if the decoder LSI (microcontroller) does
not detect LN21 falling edges.
Activity within a given frame (MOD1: low)
Transfer of 16 data bits
Data in which all
16 bits are zero
Figure 5 Transferring caption data from the LC74785/M to the decoder LSI (microcontroller): Method 2
(When it is not possible to allocate a port on the decoder LSI (microcontroller) to detect
falling edges on LN21.)
Since data is output to the output buffer once (during the even field) when MOD1 is low, the data transfer control
operation from the decoder LSI (microcontroller) must be performed at least twice in a single frame (about 32 ms).
If a transfer control operation is performed twice in the same frame, the CPDT output on the second operation will be 16
bits of zero data. This allows the decoder LSI to determine that the data for the next frame has not been transferred yet.
Note: If CS2 remains low, the hardware will not be able to transfer the data to the output buffer. Therefore, the decoder LSI (microcontroller) must reset CS2
to high from low after it completes a data transfer control operation.
Transfer method 2 cannot be used if MOD1 is high (NTSC-TV).
No. 5520-8/24
Pedestal clamp
Data peak hold
(data slice)
Data output
buffer
8-bit latch
+
command
decode
Character
output dot
clock
generator
HSYNC peak hold
(HSYNC slice)
Data slicer
Output control
Serial to
parallel
converter
Composite
sync signal
separation
control
Synchronization
determination
Vertical size
counter
Vertical
character
size register
Timing generator
Horizontal
size counter
Horizontal
character
size register
Vertical
display
position
detector
Line control
counter
Horizontal
display
position
detector
Character
control
counter
Synchronizing
signal generator
Vertical dot
counter
Vertical
display
position
register
Horizontal dot
counter
Horizontal
display
position
detector
Display
control
register
Character output control
Background control
Video output control
Blinking and
reverse video
control circuit
Blinking and
reverse video
control
register
RAM write
address
counter
Shift register
Font ROM
Decoder
Display RAM
LC74785, LC74785M
System Block Diagram
Decoder
No. 5520-9/24
LC74785, LC74785M
Display Control Commands
Display control commands have an 8-bit format and are transferred using the serial input function. Commands consist of
a command identification code in the first byte and command data in the following bytes. The following commands are
supported.
1 COMMAND0:
2 COMMAND1:
3 COMMAND2:
4 COMMAND3:
5 COMMAND4:
6 COMMAND5:
7 COMMAND6:
8 COMMAND7:
9 COMMAND8:
10 COMMAND9:
11 COMMAND10:
Display memory (VRAM) write address setup command
Display character data write command
Vertical display start position and vertical character size setup command
Horizontal display start position and horizontal character size setup command
Display control setup command
Display control setup command
Synchronizing signal detection setup command
Display control setup command
Display control setup command
Display control setup command
Display control setup command
Display Control Command Table
First byte
Command
Second byte
Command identification code
Data
Data
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
COMMAND0
Write address setup
1
0
0
0
V3
V2
V1
V0
0
0
0
H4
H3
H2
H1
H0
COMMAND1
Character write
1
0
0
1
0
0
0
0
at
c6
c5
c4
c3
c2
c1
c0
COMMAND2
Vertical character size and
vertical display start position
1
0
1
0
VS
21
VS
20
VS
11
VS
10
0
FS
VP
5
VP
4
VP
3
VP
2
VP
1
VP
0
COMMAND3
Horizontal character size and
horizontal display start position
1
0
1
1
HS
21
HS
20
HS
11
HS
10
0
LC
HP
5
HP
4
HP
3
HP
2
HP
1
HP
0
COMMAND4
Display control
1
1
0
0
OSC
STP
SYS
RST
0
BLK
2
BLK
1
BLK
0
BK
1
BK
0
RV
DSP
ON
COMMAND5
Display control
1
1
0
1
0
HLF
TON
NON
INT
0
0
0
BCL
CB
PH
2
PH
1
PH
0
COMMAND6
Synchronizing signal detection
1
1
1
0
SEL
0
MOD
0
DIS
LIN
MUT
0
RN
2
RN
1
RN
0
SN
3
SN
2
SN
1
SN
0
COMMAND7
Display control
1
1
1
1
0
0
SEL
1
CTL
3
0
0
0
VNP
SEL
VSP
SEL
MSK
ERS
MSK
SEL
EGL
COMMAND8
Display control
1
1
1
1
0
1
SEL
2
MOD
1
0
LNA
3
LNA
2
LNA
1
LNA
0
LPA
2
LPA
1
LPA
0
COMMAND9
Display control
1
1
1
1
1
0
LNB
SEL
MOD
2
0
LNB
3
LNB
2
LNB
1
LNB
0
LPB
2
LPB
1
LPB
0
COMMAND10
Display control
1
1
1
1
1
1
LNC
SEL
MOD
3
0
LNC
3
LNC
2
LNC
1
LNC
0
LPC
2
LPC
1
LPC
0
TST RAM
MOD ERS
Once written, the command identification code in the first byte is stored until the next first byte is written. However,
when the display character data write command (COMMAND1) is written, the LC74785/M locks into the display
character data write mode, and another first byte cannot be written.
When the CS1 pin is set high, the LC74785/M is set to the COMMAND0 (display memory write address setup mode)
state.
No. 5520-10/24
LC74785, LC74785M
COMMAND0 (Display memory write address setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
0
5
—
0
4
—
0
3
V3
2
V2
1
V1
0
V0
State
Function
Notes
Command 0 identification code
Sets the display memory write address.
0
1
0
1
Display memory line address (0 to B hexadecimal)
0
1
0
1
Second byte
Contents
DA
0 to 7
Register
7
—
0
6
—
0
5
—
0
4
H4
3
H3
2
H2
1
H1
0
H0
State
Function
Notes
Second byte identification code
0
1
0
1
0
1
Display memory column address (0 to 17 hexadecimal)
0
1
0
1
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
COMMAND1 (Display character data write setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
0
5
—
0
4
—
1
3
—
0
2
—
0
1
—
0
0
—
0
State
Function
Command 1 identification code
Sets up display character data write mode.
Notes
When this command is input, the LC74785/M
locks in the display character data write mode
until the CS1 pin goes high.
No. 5520-11/24
LC74785, LC74785M
Second byte
DA
0 to 7
Register
7
at
6
c6
5
c5
4
c4
3
c3
2
c2
1
c1
0
c0
Contents
State
Notes
Function
0
Character attribute off
1
Character attribute on
0
1
0
1
0
1
0
Character code (00 to 7F hexadecimal)
1
0
1
0
1
0
1
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
COMMAND2 Vertical display start position and vertical character size setup command
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
0
5
—
1
4
—
3
2
1
0
VS21
VS20
VS11
VS10
State
Notes
Function
Command 2 identification code
Sets the vertical display start position and the vertical character size
0
0
VS20
0
1
0
0
1H/dot
2H/dot
1
1
3H/dot
1H/dot
1
VS21
0
VS10
0
1
0
0
1H/dot
2H/dot
1
1
3H/dot
1H/dot
1
VS11
Second line vertical character size
First line vertical character size
Second byte
DA
0 to 7
Register
7
—
6
5
4
FS
VP5
(MSB)
VP4
3
VP3
2
VP2
1
0
VP1
VP0
(LSB)
Contents
State
0
Second byte identification bit
0
Crystal oscillator frequency: 2fsc
1
Crystal oscillator frequency: 4fsc
0
If VS is the vertical display start position then:
5
VS = H × (2 Σ 2n VPn)
n=0
H: the horizontal synchronization pulse period
1
0
1
Notes
Function
0
The vertical display start position is set by the
6 bits VP0 to VP5.
The weight of bit 1 is 2H.
1
0
1
0
1
0
Character display
area
1
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
No. 5520-12/24
LC74785, LC74785M
COMMAND3 (Horizontal display start position and horizontal size setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
0
5
—
1
4
—
1
3
HS21
2
HS20
1
HS11
0
HS10
State
Notes
Function
Command 3 identification code
Sets the horizontal display start position and the horizontal character size.
0
HS20
0
1
0
0
1Tc/dot
2Tc/dot
1
1
3Tc/dot
1Tc/dot
1
HS21
0
HS10
0
1
0
0
1Tc/dot
2Tc/dot
1
1
3Tc/dot
1Tc/dot
1
HS11
Second line horizontal character size
First line horizontal character size
Second byte
DA
0 to 7
Register
7
—
6
LC
5
HP5
(MSB)
4
HP4
3
HP3
2
HP2
1
HP1
0
HP0
(LSB)
Contents
State
Function
0
Second byte identification bit
0
Use the LC oscillator for the dot clock
1
Use the crystal oscillator for the dot clock
0
If HS is the horizontal start position then:
5
HS = Tc × (2 Σ 2n HPn)
n=0
Tc: Period of the oscillator connected to OSCIN/OSCOUT in operating
mode.
1
0
1
0
1
0
Notes
Selects the dot clock used for character
display in the horizontal direction.
The horizontal display start position is set by
the 6 bits HP0 to HP5.
The weight of bit 1 is 2Tc.
1
0
1
0
1
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
No. 5520-13/24
LC74785, LC74785M
COMMAND4 (Display control setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
1
5
—
0
4
—
0
3
TSTMOD
2
RAMERS
1
OSCSTP
0
SYSRST
State
Notes
Function
Command 4 identification code
Display control setup
0
Normal operating mode
1
Test mode
This bit must be set to 0.
0
Erasing RAM takes about 500 µs. (This operation
must be executed in the DSPOFF state.)
1
Erase display RAM. (Set the RAM data to 7F hexadecimal.)
0
Do not stop the crystal and LC oscillators.
1
Stop the crystal and LC oscillators.
Valid in external synchronization mode when
character display is off.
Reset all registers and turn display off.
The registers are reset when the CS1 pin is low,
and the reset state is cleared when CS1 is set high,
0
1
Second byte
DA
0 to 7
Register
7
—
6
BLK2
5
BLK1
4
BLK0
3
BK1
2
1
0
BK0
RV
DSPON
Contents
State
Notes
Function
0
Second byte identification bit
0
Character display area
1
Video display area
Specifies the size for complete fill in
0
BLK0
0
1
0
0
Blanking off
Character size
1
1
Border size Full character size
BLK1
1
0
Changes the blanking size
Blinking period: About 0.5 s
1
Blinking period: About 1.0 s
0
Blinking off
1
Blinking on
0
Reverse (character reversing) off
1
Reverse (character reversing) on
0
Character display off
1
Character display on
Switches the blinking period
Blinking in reverse video mode switches the display between
normal character display and reverse video display.
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
No. 5520-14/24
LC74785, LC74785M
COMMAND5 (Display control setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
1
5
—
0
4
—
1
3
—
0
2
HLFTON
1
NON
0
INT
State
Notes
Function
Command 5 identification code
Display control setup
0
External synchronizing signal judgment output signal
1
A signal in the range specified by LNA*, LNB*, and LNC* is output.
0
Interlaced
1
Noninterlaced
0
External synchronization
1
Internal synchronization
Switches the SYNCJDG (pin 8) output.
Switches between interlaced and
noninterlaced video.
Switches between external and internal
synchronization
Second byte
Contents
DA
0 to 7
Register
7
—
0
6
—
0
5
—
4
BCL
3
CB
2
PH2
State
0
Background coloring on
1
No background coloring (Only the background level is set)
0
Color burst signal output.
1
Color burst signal output stopped.
1
0
PH1
1
0
0
Second byte identification bit
0
0
1
Notes
Function
PH0
1
Only valid in internal synchronization mode.
Only valid when BCL is high.
PH2
PH1
PH0
0
0
0
Background color (phase)
Cyan
0
0
1
Yellow
*
0
1
0
Red
*
*
0
1
1
Blue
1
0
0
Cyan - blue
1
0
1
Green
1
1
0
Orange
1
1
1
Magenta
*
Background color specification
*
*
*: When 2 fsc is used.
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
No. 5520-15/24
LC74785, LC74785M
COMMAND6 (Synchronizing signal detection setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
1
5
—
1
4
—
3
SEL0
2
MOD0
1
DISLIN
0
MUT
State
Notes
Function
Command 6 identification code
Sets up synchronizing signal control.
0
0
Sync separator signal
1
Output signal set by MOD0
0
High-level output
1
ST pulse signal
0
12 lines
1
10 lines
0
Normal output
1
CVIN is cut and CVOUT is held at the pedestal level.
Switches the SEPOUT (pin 19) output.
Only valid when SEL0 is high.
Switches the number of lines displayed.
CVOUT switching
Second byte
DA
0 to 7
Register
7
—
6
5
4
3
2
RN2
RN1
RN0
SN3
SN2
1
SN1
0
SN0
Contents
State
0
0
1
0
1
0
1
Notes
Function
Second byte identification bit
RN2
RN1
RN0
Number of times HSYNC detected
0
0
0
0 times
0
0
1
4 times
0
1
0
8 times
1
0
0
16 times
External synchronizing signal detection control
Signal absent → signal present transition
detection
Sets the sampling period in which SYNC can
be detected continuously in the horizontal
synchronizing signal period (1H).
0
1
SN3
SN2
SN1
SN0
Number of times HSYNC detected
0
0
0
0
0
Not detected
32 times
1
0
0
0
1
0
0
0
1
0
64 times
1
0
1
0
0
128 times
0
1
0
0
0
256 times
External synchronizing signal detection control
Signal present → signal absent transition
detection
Sets the sampling period in which SYNC
cannot be detected continuously in the
horizontal synchronizing signal period (1H).
1
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
No. 5520-16/24
LC74785, LC74785M
COMMAND7 (Display control setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
1
5
—
1
4
—
1
3
—
0
2
—
0
1
SEL1
0
CTL3
State
Function
Notes
Command 7 identification code
Display control setup
Extended command 0 identification code
0
Vertical synchronizing signal (external V separation) input
1
Frame signal input
0
Use internal V separation.
1
Do not use internal V separation.
Switches the SEPIN (pin 20) input.
Only valid when CTL3 is high.
Switches V separation.
Second byte
Contents
DA
0 to 7
Register
7
—
0
6
—
0
5
—
4
VNPSEL
3
VSPSEL
2
MSKERS
1
MSKSEL
0
EGL
State
Function
Notes
Second byte identification bit
0
0
V falling edge detection
1
V rising edge detection
0
VSEP: about 8.9 µs
1
VSEP: about 17.8 µs
0
Mask valid
1
Mask invalid
0
3H
1
20H
0
Border level 0 only (VBK0)
1
Two-stage border level (VBK0 and VBK1)
Switches the V acquisition polarity in external
mode when internal V separation is used.
Switches the internal V separation period.
Clears the HSYNC and VSYNK masks.
Switches the VSYNC mask.
Switches the border level.
(Only valid when BLK0 is 0 and BLK1 is 1.)
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
No. 5520-17/24
LC74785, LC74785M
COMMAND8 (Display control setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
1
5
—
1
4
—
1
3
—
0
2
—
1
1
SEL2
0
MOD1
State
Notes
Function
Command 8 identification code
Display control setup
Extended command 1 identification code
0
External synchronizing signal judgment output signal
1
O/E signal
0
Even field line 21 data extraction (VCR)
1
Line 21 data extraction on both odd and even fields (NTSC-TV)
Switches the SYNCJDG (pin 8) output
Valid when HLFTON is low.
Switches line 21 data extraction.
Second byte
DA
0 to 7
Register
7
—
6
LNA3
Contents
State
0
0
1
0
5
LNA2
1
0
4
LNA1
1
0
3
LNA0
Notes
Function
Second byte identification bit
LNA3 LNA2 LNA1 LNA0
Specified line
0
0
0
0
Do not change the line background
0
0
0
1
Line 1
0
0
1
0
Line 2
0
0
1
1
Line 3
0
1
0
0
Line 4
0
1
0
1
Line 5
0
1
1
0
Line 6
0
1
1
1
Line 7
1
0
0
0
Line 8
1
0
0
1
Line 9
1
0
1
0
Line 10
1
0
1
1
Line 11
1
1
—
—
Line 12
Specifies the line whose background is to be
changed
(If the same line is specified to have different
background colors with LNA*, LNB*, and
LNC*, then the setting specified by the last
command issued will be valid. The previously
specification registers (LN* and LP*) will all be
reset to 0.)
1
0
2
LPA2
1
0
1
LPA1
1
0
0
LPA0
1
LPA2
LPA1
LPA0
0
0
0
Background color (phase)
Cyan
0
0
1
Yellow
*
0
1
0
Red
*
*
0
1
1
Blue
1
0
0
Cyan - blue
1
0
1
Green
1
1
0
Orange
1
1
1
Magenta
*
Specifies the background color.
*
*
*: When 2 fsc is used.
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
No. 5520-18/24
LC74785, LC74785M
COMMAND9 (Display control setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
1
5
—
1
4
—
1
3
—
1
2
—
0
1
LNBSEL
0
MOD2
State
Notes
Function
Command 9 identification code
Display control setup
Extended command 2 identification code
0
Normal line background color operation
1
RV characters have the background color specified by PH* or the RV
character background color is white.
0
LNBSEL: 1 setting specification
1
RV characters have the background color specified by PH*, characters are white.
Switches the RV mode background color for
the line specified by LNB* for characters
specified for RV display.
Valid when LNBSEL is high
Second byte
DA
0 to 7
Register
7
—
6
LNB3
Contents
State
0
0
1
0
5
LNB2
1
0
4
LNB1
1
0
3
LNB0
Notes
Function
Second byte identification bit
LNB3 LNB2 LNB1 LNB0
Specified line
0
0
0
0
Do not change the line background
0
0
0
1
Line 1
0
0
1
0
Line 2
0
0
1
1
Line 3
0
1
0
0
Line 4
0
1
0
1
Line 5
0
1
1
0
Line 6
0
1
1
1
Line 7
1
0
0
0
Line 8
1
0
0
1
Line 9
1
0
1
0
Line 10
1
0
1
1
Line 11
1
1
—
—
Line 12
Specifies the line whose background is to be
changed
(If the same line is specified to have different
background colors with LNA*, LNB*, and
LNC*, then the setting specified by the last
command issued will be valid. The previously
specification registers (LN* and LP*) will all be
reset to 0.)
1
0
2
LPB2
1
0
1
LPB1
1
0
0
LPB0
1
LPB2
LPB1
LPB0
0
0
0
Background color (phase)
Cyan
0
0
1
Yellow
*
0
1
0
Red
*
*
0
1
1
Blue
1
0
0
Cyan - blue
1
0
1
Green
1
1
0
Orange
1
1
1
Magenta
*
Specifies the background color.
*
*
*: When 2 fsc is used.
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
No. 5520-19/24
LC74785, LC74785M
COMMAND10 (Display control setup command)
First byte
Contents
DA
0 to 7
Register
7
—
1
6
—
1
5
—
1
4
—
1
3
—
1
2
—
0
1
LNCSEL
0
MOD3
State
Notes
Function
Command 10 identification code
Display control setup
Extended command 2 identification code
0
Normal line background color operation
1
RV characters have the background color specified by PH* or the RV
character background color is white.
0
LNCSEL: 1 setting specification
1
RV characters have the background color specified by PH*, characters are white.
Switches the RV mode background color for
the line specified by LNC* for characters
specified for RV display.
Valid when LNCSEL is high
Second byte
DA
0 to 7
Register
7
—
6
LNC3
Contents
State
0
0
1
0
5
LNC2
1
0
4
LNC1
1
0
3
LNC0
Notes
Function
Second byte identification bit
LNC3 LNC2 LNC1 LNC0
Specified line
0
0
0
0
Do not change the line background
0
0
0
1
Line 1
0
0
1
0
Line 2
0
0
1
1
Line 3
0
1
0
0
Line 4
0
1
0
1
Line 5
0
1
1
0
Line 6
0
1
1
1
Line 7
1
0
0
0
Line 8
1
0
0
1
Line 9
1
0
1
0
Line 10
1
0
1
1
Line 11
1
1
—
—
Line 12
Specifies the line whose background is to be
changed.
(If the same line is specified to have different
background colors with LNA*, LNB*, and
LNC*, then the setting specified by the last
command issued will be valid. The previously
specification registers (LN* and LP*) will all be
reset to 0.)
1
0
2
LPC2
1
0
1
LPC1
1
0
0
LPC0
1
LPC2
LPC1
LPC0
0
0
0
Background color (phase)
Cyan
0
0
1
Yellow
*
0
1
0
Red
*
*
0
1
1
Blue
1
0
0
Cyan - blue
1
0
1
Green
1
1
0
Orange
1
1
1
Magenta
*
Specifies the background color.
*
*
*: When 2 fsc is used.
Note: All registers are set to 0 when the LC74785/M is reset by the RST pin.
No. 5520-20/24
LC74785, LC74785M
Display Screen Structure
The display consists of 12 lines of 24 characters.
Up to 288 characters can be displayed.
The number of characters that can be displayed is reduced when enlarged characters are displayed.
Display memory addresses are specified as row (0 to 11 decimal) and column (0 to 23 decimal) addresses.
Display Screen Structure (display memory addresses)
24 Characters
12 Rows
No. 5520-21/24
LC74785, LC74785M
Composite Video Signal Output Levels (internally generated levels)
CVOUT output level waveform (VDD2 = 5.00 V)
Output level
Output voltage (1) [V]
Output voltage (2) [V]
Output voltage (3) [V]
Character
2.67
2.87
3.16
VRSH0: High for background
colors other than blue
2.45
2.64
2.93
VRSH1,2 High for blue background colors 1 and 2
2.09
2.29
2.58
VBK1:
Border 1
2.09
2.29
2.58
VCBH:
High for the color
burst signal
1.75
1.95
2.23
1.61
1.80
2.09
VCHA:
VRSL2: Low for blue background color 2
VBK0:
Border 0
1.52
1.72
2.01
VPD:
Pedestal level
1.44
1.64
1.93
1.29
1.48
1.77
VRSL0: Low for background
colors other than blue
VRSL1
Low for blue background color 1
1.20
1.39
1.68
VCBL:
Low for the color
burst signal
1.10
1.29
1.58
VSN:
Sync
0.82
1.01
1.30
Note: VDD2 = 5.0 V.
No. 5520-22/24
LC74785, LC74785M
Sample Application Circuit (When the LC74785/M is used in conjunction with a single-chip Y/C circuit.)
Microprocessor
External system clock input
Microprocessor
Crystal oscillator
Microprocessor
External system clock input (when the pin 3 and 4 functions are modified by mask options)
Note: When a sync tip level of 1.3 V DC (CVIN input signal: sync tip = 1.3 V) is selected for the internal generated video signals by option settings, the
electrolytic capacitor connected to SYNIN must be connected with the correct polarity.
When VDD1 is 5.0 V, the SYNIN input video signal pedestal level is clamped at about 2.5 V DC.
No. 5520-23/24
LC74785, LC74785M
■ No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace
equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of
which may directly or indirectly cause injury, death or property loss.
■ Anyone purchasing any products described or contained herein for an above-mentioned use shall:
➀ Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and
distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all
damages, cost and expenses associated with such use:
➁ Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on
SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees
jointly or severally.
■ Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for
volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied
regarding its use or any infringements of intellectual property rights or other rights of third parties.
This catalog provides information as of June, 1997. Specifications and information herein are subject to change
without notice.
No. 5520-24/24