LM1253AN National Semiconductor, LM1253AN Datasheet - Page 41

• Manufacturer Part Number: LM1253AN
• Description: Monolithic Triple 180 MHz I2C CRT Pre-amp With Integrated Analog On Screen Display (OSD) Generator
• Manufacturer: National Semiconductor

Control Register Definitions
Vertical Blank Duration Control Register (I
REGISTER NAME: VBLANKDUR
Bits 6–0: Vertical Blank Duration. These seven bits set the duration of the VBLANK signal in numbers of horizontal scan lines.
Bit 7:
OSD Character Height Control Register (I
REGISTER NAME: CHARHTCTRL
Bits 7–0: Character Height: this register sets the character height according to the constant character height mechanism de-
Button Box Highlight Color Register (EF1) (I
REGISTER NAME: BBHLCTRLB1 (8406h) BBHLCTRLB0 (8405h)
Bit 15
Bits 8–0:
Bits 15–9:
Button Box Lowlight Color Register (EF2) (I
REGISTER NAME: BBLLCTRLB1 (8408h) BBLLCTRLB0 (8407h)
Bit 15
Bits 8–0:
Bits 15–9:
Heavy Button Box Lowlight/Shadow/Shading Color Register (EF3) (I
REGISTER NAME: CHSDWCTRLB1 (840Ah) CHSDWCTRLB0 (8409h)
Bit 15
Bits 8–0:
Bits 15–9: RESERVED.
Bit 7
Bit 7
RSV
RSV
RSV
RSV
CH7
RSV
RSV
RSV
CH6
VB6
RESERVED.
scribed in section Constant Character Height Mechanism. The value programmed in the register is equal to the ap-
proximate number of OSD height compensated lines required on the screen divided by 4. The value is only approxi-
mate, due to the approximation used in scaling the characters.
Example: If approximately 384 OSD lines are required on the screen (regardless of the number of image lines) then
the Character Height Control Register is programmed with the value of 81.
Heavy Button Box lowlight/shadow color. This register indicates the value of Enhanced Feature (heavy button box
lowlight or shadow/shading) register EF3.
Button Box highlight color. This register indicates the value of Enhanced Feature (button box highlight) register EF1.
RESERVED.
Button Box lowlight color. This register indicates the value of Enhanced Feature (button box lowlight) register EF2.
RESERVED.
RSV
RSV
RSV
CH5
VB5
RSV
RSV
RSV
CH4
VB4
RSV
RSV
RSV
CH3
VB3
RSV
RSV
RSV
CH2
VB2
2
2
C address 8404h).
C address 8403h).
2
2
RSV
RSV
RSV
C address 8407h–8408h).
CH1
VB1
(Continued)
C address 8405h–8406h).
Bit 8
Bit 8
Bit 8
CH0
VB0
Bit 0
Bit 0
R2
R2
R2
41
Bit 7
Bit 7
Bit 7
R1
R1
R1
R0
R0
R0
2
C address 8409h–840Ah).
B2
B2
B2
B1
B1
B1
B0
B0
B0
G2
G2
G2
G1
G1
G1
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G0
G0
G0
Bit 0
Bit 0
Bit 0