EM78468AQ EMC [ELAN Microelectronics Corp], EM78468AQ Datasheet - Page 18

• Manufacturer Part Number: EM78468AQ
• Description: 8-BIT Microcontroller
• Manufacturer: EMC [ELAN Microelectronics Corp]

EM78468
8-BIT Microcontroller
14 •
4.1.10 R9/LCDCR (LCD Control Register)
4.1.11 RA/LCD_ADDR (LCD Address)
Bit 7 (BS): LCD bias select bit,
Bit 6 ~ 5 (DS1 ~ DS0): LCD duty select
Bit 4 (LCDEN): LCD enable bit.
Bit 3: Not used
Bit 2 (LCDTYPE): LCD drive waveform type select bit
Bit 1 ~ 0 (LCDF1 ~ LCDF0): LCD frame frequency control bits
Fs: sub-oscillator frequency
Bit 7 ~ 5: Not used, fixed to “0”
LCDF1
Bit 7
Bit 7
BS
0
0
0
1
1
DS1
(Address: 09h)
BS = “0”: 1/2 bias
BS = “1”: 1/3 bias
LCDEN = “ 0”: LCD circuit disable, all common/segment outputs are set to ground
(GND) level.
LCDEN = “1”: LCD circuit enable
LCDTYPE = “ 0”: A type waveform
LCDTYPE = “1”: B type waveform
0
0
1
(Address: 0Ah)
LCDF0
Bit 6
DS1
Bit 6
0
0
1
0
1
DS0
X
Bit 5
0
1
DS0
Bit 5
Fs/(256*2)=64.0
Fs/(280*2)=58.5
Fs/(304*2)=53.9
Fs/(232*2)=70.6
0
1/2 duty
LCD frame frequency (e.g. Fs=32.768KHz)
LCDEN
LCD_A4
Bit 4
Bit 4
LCD duty
(This specification is subject to change without further notice)
1/2 duty
1/3 duty
1/4 duty
LCD_A3
Bit 3
Fs/(172*3)=63.5
Fs/(188*3)=58.0
Fs/(204*3)=53.5
Fs/(156*3)=70.0
Bit 3
--
Product Specification (V1.1) 04.11.2005
1/3 duty
LCDTYPE
LCD_A2
Bit 2
Bit 2
LCDF1
LCD_A1
Bit 1
Fs/(128*4) =64.0
Fs/(140*4) =58.5
Fs/(152*4) =53.9
Fs/(116*4) =70.6
Bit 1
1/4 duty
LCD_A0
LCDF0
Bit 0
Bit 0