EM78808
8-bit Micro-controller
Bit 3~Bit 4(LCDDV0~LCDDV1) : LCD driver’s driving ability control
LCDDV1
LCDDV0 Driving mode
0
0
1
1
0
1
0
1
Normal mode (ratio = 1)
Weak mode (ratio = 1/2)
Strong mode (ratio = 2)
Maximum mode (ratio = 4)
LCDDV0 ~ LCDDV1 are used to select the driving ability of LCD driver. The driving ability is Maximum
mode > Strong mode > Normal mode > Weak mode by 1/2 ratio individually. The larger driving ability it is
selected, the larger output loading of LCD driver output can be afforded and the more current consumption is
occurred. It depends on user’s application.
Bit 5(PBS) : Switch I/O PORTB or LCD segment output for share pins SEGxx/PBx
0 ꢂselect normal PB0 ~ PB7 for PORTB
1 ꢂselect SEG48 ~ SEG55 output for LCD SEGMENT output.
Bit 6(PCSL) : Switch low nibble I/O PORTC or LCD segment output for share pins SEGxx/PCx
0 ꢂselect normal PC0 ~ PC3 for low nibble PORTC
1 ꢂselect SEG56 ~ SEG59 output for LCD SEGMENT output.
Bit 7(PCSH) : Switch high nibble I/O PORTC or LCD segment output for share pins SEGxx/PCx
0 ꢂselect normal PC4 ~ PC7 for high nibble PORTC
1 ꢂselect SEG60 ~ SEG63 output for LCD SEGMENT output.
IOC7 (PORT7 I/O control, Key strobe(8~15))
PAGE0 (PORT7 I/O control register)
7
6
5
4
3
2
1
0
IOC77
IOC76
IOC75
IOC74
IOC73
IOC72
IOC71
IOC70
Bit 0~Bit 7(IOC70~IOC77) : PORT7(0~7) I/O direction control register
0 ꢂput the relative I/O pin as output
1 ꢂput the relative I/O pin into high impedance
PAGE1 (Key strobe control register)
7
6
5
4
3
2
1
0
STRB15 STRB14 STRB13 STRB12 STRB11 STRB10
STRB9
STRB8
Bit 0~Bit 7(STRB8~STRB15) : Key strobe control bits
These key strobe control registers correspond to SEGMENT8 to SEGMENT15. Please refer KEYSTOBE
explanation (RE page0).
IOC8 (PORT8 I/O control, , Key strobe(16~23))
PAGE0 (PORT8 I/O control register)
7
6
5
4
3
2
1
0
IOC87
IOC86
IOC85
IOC84
IOC83
IOC82
IOC81
IOC80
Bit 0~Bit 7(IOC80~IOC87) : PORT8(0~7) I/O direction control register
0 ꢂput the relative I/O pin as output
1 ꢂput the relative I/O pin into high impedance
PAGE1 (Key strobe control register)
7
6
5
4
3
2
1
0
STRB23 STRB22 STRB21 STRB20 STRB19 STRB18 STRB17 STRB16
Bit 0~Bit 7(STRB16~STRB23) : Key strobe control bits
These key strobe control registers correspond to SEGMENT16 to SEGMENT23. Please refer KEYSTOBE
explanation (RE page0).
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* This specification is subject to change without notice.
8/1/2004 (V3.1)
35
ELAN [ ELAN MICROELECTRONICS CORP ]
