4554 Datasheet, PDF (48/138 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4554 Group
Table 12 LCD control registers
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
Off
1
On
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 VLC3/SEG0 pin function switch bit (Note 3)
0
SEG0
1
VLC3
L22 VLC2/SEG1 pin function switch bit (Note 4)
0
SEG1
1
VLC2
L21 VLC1/SEG2 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 : 00002
SEG24/P33–SEG27/P30 pin function
L33
switch bit
0
SEG24–SEG27
1
P33–P30
SEG28/P23, SEG29/P22 pin function
L32
switch bit
0
SEG28, SEG29
1
P23, P22
SEG30/P21 pin function
L31
switch bit
0
SEG30
1
P21
SEG31/P20 pin function
L30
switch bit
0
SEG31
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.
at power down : state retained
W
TL3A
Rev.3.00 Aug 06, 2004 page 48 of 136
REJ03B0043-0300Z