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EM78P468N/EM78P468L
8-Bit Microcontroller
10 •
Product Specification (V1.5) 02.15.2007
(This specification is subject to change without further notice)
6.1.9 R8/Port 8 (Port 8 I/O Data Register)
(Address: 08h)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
R87 R86 R85 R84 R83 R82 R81 R80
Bits 7~0: 8-bit I/O registers of Port 8
User can use IOC80 register to define each bit either as input or output.
6.1.10 R9/LCDCR (LCD Control Register)
(Address: 09h)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
BS DS1 DS0 LCDEN -- LCDTYPE LCDF1 LCDF0
Bit 7 (BS): LCD bias select bit,
BS = “0”: 1/2 bias
BS = “1”: 1/3 bias
Bit 6 ~ 5 (DS1 ~ DS0): LCD duty select
DS1 DS0 LCD Duty
0 0 1/2 duty
0 1 1/3 duty
1 × 1/4 duty
Bit 4 (LCDEN): LCD enable bit
LCDEN = “0”: LCD circuit disabled. All common/segment outputs are set to
ground (GND) level.
LCDEN = “1”: LCD circuit enabled.
Bit 3: Not used
Bit 2 (LCDTYPE): LCD drive waveform type select bit
LCDTYPE = “0” : A type waveform
LCDTYPE = “1” : B type waveform
Bits 1 ~ 0 (LCDF1 ~ LCDF0): LCD frame frequency control bits
LCD Frame Frequency (e.g. Fs=32.768kHz)
LCDF1 LCDF0
1/2 Duty 1/3 Duty 1/4 Duty
0 0 Fs/(256×2)=64.0 Fs/(172×3)=63.5 Fs/(128×4)=64.0
0 1 Fs/(280×2)=58.5 Fs/(188×3)=58.0 Fs/(140×4)=58.5
1 0 Fs/(304×2)=53.9 Fs/(204×3)=53.5 Fs/(152×4)=53.9
1 1 Fs/(232×2)=70.6 Fs/(156×3)=70.0 Fs/(116×4)=70.6
Note: Fs: sub-oscillator frequency