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EM78P468N/EM78P468L
8-Bit Microcontroller
6.1.9
R8/Port 8 (Port 8 I/O Data Register)
(Address: 08h)
Bit 7
R87
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
BS
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
0
0
1
Bit 4 (LCDEN): LCD enable bit
LCDEN = "0": LCD circuit disabled. All common/segment outputs are set to
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
LCDF1
0
0
1
1
Note: Fs: sub-oscillator frequency
10 •
Bit 6
Bit 5
Bit 4
R86
R85
R84
Bit 6
Bit 5
Bit 4
DS1
DS0
LCDEN
DS0
LCD Duty
0
1
×
ground (GND) level.
LCD Frame Frequency (e.g. Fs=32.768kHz)
LCDF0
1/2 Duty
0
Fs/(256×2)=64.0
1
Fs/(280×2)=58.5
0
Fs/(304×2)=53.9
1
Fs/(232×2)=70.6
Bit 3
Bit 2
R83
R82
Bit 3
Bit 2
--
LCDTYPE
1/2 duty
1/3 duty
1/4 duty
1/3 Duty
Fs/(172×3)=63.5
Fs/(188×3)=58.0
Fs/(204×3)=53.5
Fs/(156×3)=70.0
Product Specification (V1.5) 02.15.2007
(This specification is subject to change without further notice)
Bit 1
Bit 0
R81
R80
Bit 1
Bit 0
LCDF1
LCDF0
1/4 Duty
Fs/(128×4)=64.0
Fs/(140×4)=58.5
Fs/(152×4)=53.9
Fs/(116×4)=70.6
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