4552 Datasheet, PDF (44/145 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4552 Group
Table 12 LCD control registers (1)
LCD control register L1
Internal dividing resistor for LCD power
L13
supply selection bit (Note 2)
L12
LCD control bit
L11
LCD duty and bias selection bits
L10
at reset : 00002
0
2r ✕ 3, 2r ✕ 2
1
r ✕ 3, r ✕ 2
0
Stop
1
Operating
L11 L10
Duty
00
01
1/2
10
1/3
11
1/4
at power down : state retained
R/W
TAL1/TL1A
Bias
Not available
1/2
1/3
1/3
LCD control register L2
at reset : 00002
at power down : state retained
L23
SEG0/VLC3 pin function switch bit (Note 3)
0
SEG0
1
VLC3
L22
SEG1/VLC2 pin function switch bit (Note 4)
0
SEG1
1
VLC2
L21
SEG2/VLC1 pin function switch bit (Note 4)
0
SEG2
1
VLC1
L20
Internal dividing resistor for LCD power
supply control bit
0
Internal dividing resistor valid
1
Internal dividing resistor invalid
W
TL2A
LCD control register L3
at reset : 11112
at power down : state retained
L33
P23/SEG20 pin function switch bit
L32
P22/SEG19 pin function switch bit
L31
P21/SEG18 pin function switch bit
L30
P20/SEG17 pin function switch bit
0
SEG20
1
P23
0
SEG19
1
P22
0
SEG18
1
P21
0
SEG17
1
P20
Notes 1: “R” represents read enabled, and “W” represents write enabled.
2: “r (resistor) multiplied by 3” is used at 1/3 bias, and “r multiplied by 2” is used at 1/2 bias.
3: VLC3 is connected to VDD internally when SEG0 pin is selected.
4: Use internal dividing resistor when SEG1 and SEG2 pins are selected.
W
TL3A
Rev.3.02 Dec 22, 2006 page 44 of 142
REJ03B0023-0302