EM78862B Datasheet, PDF (21/40 Pages) ELAN Microelectronics Corp – 8-Bit RISC Type Microprocessor

Com2
Seg
EM78862B
8-Bit RISC Type Microprocessor
vdd
v1
v2
v3
vlcd
Gnd
vdd
v1
v2
v3
vlcd
Gnd
30us
Fig. 8 Key Scan Signal
Bit 1: Port 7 PULL HIGH register option. Use default value.
Bit 2 ~ 4: (BIAS1~BIAS3) Control bits are used to choose LCD operation voltage.
BIAS3
0
0
0
0
1
1
1
1
BIAS2
0
0
1
1
0
0
1
1
BIAS1
0
1
0
1
0
1
0
1
Ratio
0.60 VDD
0.66 VDD
0.74 VDD
0.82 VDD
0.87 VDD
0.93 VDD
0.96 VDD
1.00 VDD
LCD Vop (VDD=5V)
3.0V
3.3V
3.7V
4.0V
4.4V
4.7V
4.8V
5.0V
Bit 5:
(P6S) Port 6 switch
0: Normal I/O port
1: Common output of LCD
Bit 6:
(P9SL) Port 9 low nibble switch
0: Normal I/O port
1: Segment output of LCD
Bit 7:
(P9SH) Port 9 high nibble switch
0: Normal I/O port
1: Segment output of LCD
This specification is subject to change without further notice.
Mar.01.2005 (V1.1)17 of 36