455A Datasheet, PDF (79/148 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

455A Group
Timer control register W5
W53 Not used
W52 Not used
W51
Timer 3 count source selection bits
W50
LCD control register L1
L13
Internal dividing resistor for LCD power
supply selection bit (Note 2)
L12 LCD control bit
L11
LCD duty and bias selection bits
L10
at reset : 00002
at power down : state retained
0 This bit has no function, but read/write is enabled.
1 This bit has no function, but read/write is enabled.
0 This bit has no function, but read/write is enabled.
1 This bit has no function, but read/write is enabled.
W51 W52
Count source
00
XCIN input
01
ORCLK input
10
Low-speed on-chip oscillator
11
High-speed on-chip oscillator
R/W
TAW5/TW5A
at reset : 00002
at power down : state retained
0 2r × 3, 2r × 2
1 r × 3, r × 2
0 Stop (OFF)
1 Operating
L11 L1
Duty
0 0 Not available
0 1 1/2
1 0 1/3
1 1 1/4
Bias
Not available
1/2
1/3
1/3
R/W
TAL1/TL1A
LCD control register L2
L23 SEG0/VLC3 pin function switch bit (Note 3)
L22 SEG1/VLC2 pin function switch bit (Note 4)
L21 SEG2/VLC1 pin function switch bit (Note 4)
L20 ^{Internal dividing resistor for LCD power}
supply control bit
at reset : 00002
at power down : state retained
0 SEG0
1 VLC3
0 SEG1
1 VLC2
0 SEG2
1 VLC1
0 Internal dividing resistor valid
1 Internal dividing resistor invalid
LCD control register L3
at reset : 11112
at power down : state retained
L33 P23/SEG27 pin function switch bit
0 SEG27
1 P23
L32 P22/SEG26 pin function switch bit
0 SEG26
1 P22
L31 P21/SEG25 pin function switch bit
0 SEG25
1 P21
L30 P20/SEG24 pin function switch bit
0 SEG24
1 P20
Note 1. ”R” represents read enabled, and “W” represents write enabled.
Note 2. “r (resistor) multiplied by 3” is used at 1/3 bias, and “r multiplied by 2” is used at 1/2 bias.
Note 3. VLC3 is connected to VDD internally when SEG0 pin is selected.
Note 4. Use internal dividing resistor when SEG1 and SEG2 pins are selected.
W
TL2A
W
TL3A
Rev.1.01 Feb 15, 2008 Page 79 of 146
REJ03B0224-0101