CHAPTER 3 LCD CONTROLLER/DRIVER
User’s Manual U18438EJ2V0UD
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3.4 Registers Controlling LCD Controller/Driver
The following four registers are used to control the LCD controller/driver.
• LCD mode setting register (LCDMD)
• LCD display mode register (LCDM)
• LCD clock control register (LCDC)
• LCD voltage boost control register 0 (VLCG0)
(1) LCD mode setting register (LCDMD)
LCDMD sets the number of segments and the LCD reference voltage generator.
LCDMD is set using an 8-bit memory manipulation instruction.
Reset signal generation sets LCDMD to 00H.
Figure 3-5. Format of LCD Mode Setting Register
Address: LCDCTL's 00H
After reset:
00H R/W
Symbol
7 6 5 4 3 2 1 0
LCDMD
SEGSET2 SEGSET1 SEGSET0
0
0
0
MDSET1 MDSET0
SEGSET2
SEGSET1
SEGSET0
Segment number setting
0
1
1
36 (52-pin product)
0 0
×
40 (64-pin product)
Other than above
Setting prohibited
MDSET1
MDSET0
LCD reference voltage generator selection
0
0
External resistance division method
0
1
Internal resistance division method
1
×
Internal voltage boosting method
Cautions 1. Bits 2 to 4 must be set to 0.
2. LCDMD can be set only once after a reset release.