LM1237BDKD/NA/NOPB National Semiconductor, LM1237BDKD/NA/NOPB Datasheet - Page 33

• Manufacturer Part Number: LM1237BDKD/NA/NOPB
• Manufacturer: National Semiconductor

Specifications of LM1237BDKD/NA/NOPB

• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Package Type: MDIP
• Lead Free Status / RoHS Status: Compliant

Control Register Definitions
Character Height Register
Register Name (address): CHARHTCTRL (0x8404)
ROM Signature Control Register
Register Name (address): ROMSIGCTRL (0x840D)
ROM Signature Data Register
Enhanced Feature Register 1
Register Name (addresses): BBHLCTRLB1 (0x8406) and BBHLCTRLB0 (0x8405)
Enhanced Feature Register 2
Register Names (addresses): BBLLCTRLB1 (0x8408) and BBLLCTRLB0 (0x8407)
Enhanced Feature Register 3
Register Names (addresses): CHSDWCTRLB1 (0x840A) and CHSDWCTRLB0 (0x8409)
Bits 7–0
Bits 8–0
Bits 15–9
Bits 8–0
Bits 15–9
Bits 8–0
Bits 15–9
Bit 0
Bits 7–1
This register determines the OSD character height as described in the section Constant Character Height
Mechanism. The values of this register is equal to the approximate number of OSD height compensated lines
required on the screen, divided by 4. This value is not exact due to the approximation used in scaling the
character.
Example: If approximately 324 OSD lines are required on the screen (regardless of the number of scan lines)
then the Character Height Control Register is programmed with 81 (0x51).
These determine the button box highlight color.
Reserved. These bits should be set to zero.
These determine the button box lowlight color.
Reserved. These bits should be set to zero.
These registers determine the heavy button box lowlight, shading or shadow color.
Reserved. These bits should be set to zero.
This controls the calculation of the ROM signature. Setting this bit causes the ROM to be read sequentially
and a 16-bit checksum calculated over the 256 characters. The sum, modulo 65535, is stored in the ROM
Signature Data Register, and this bit is then automatically cleared.
Reserved. These should be set to zero.
(Continued)
33
Heavy Button Box Lowlight/Shading/Shadow
20023439
20023443
Button Box Highlight Color
Button Box Lowlight Color
20023440
20023441
20023442
www.national.com