PD17012_15 Datasheet, PDF (220/320 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DIGITAL TUNING SYSTEM HARDWARE

µPD17012, 17P012
19.3.2 Function of LCD segment register
Figure 19-4 shows the relation of 1 nibble (4 bits) of the LCD segment register and LCD display dots.
As shown in this figure, the lower 3 bits of display data (on/off data) in 1 nibble of the LCD segment register
can be set.
The LCD display dot corresponding to a bit that is set to 1 is turned on, and the dot corresponding to a bit
that is reset to 0 is turned off.
The highest one bit can be used as data memory, however data should be set carefully because the address
is the same.
LCDD19 to LCDD16 of the LCD segment register also set output data when the LCD19/P2H0 to LCD16/P2E0
pins are used as output port pins. In this case, output data is set to the least significant bit. The higher 3 bits
can be used as data memory, however data setting requires caution because the addresses are the same.
When LCD display is not used, LCDD15 to LCDD0 can be used as normal data memory.
Figure 19-5 shows the relationship between each LCD segment register and LCD display dots that are turned
on/off.
Figure 19-4. Relationship of 1 Nibble of LCD Segment Register and LCD Display Dots
LCD segment register
Address
m
Bit b3 b2 b1 b0
Can be used as
data memory
b2
COM2 pin
b1
COM1 pin
b0
COM0 pin
LCDn pin
218
Data Sheet U10101EJ4V0DS