Datasheet

RL78/L12 CHAPTER 14 LCD CONTROLLER/DRIVER
R01UH0330EJ0200 Rev.2.00 637
Dec 13, 2013
(2) Segment signals
The segment signals correspond to the LCD display data register (see 14.4 LCD Display Data Registers).
When the number of time slices is eight, bits 0 to 7 of each display data register are read in synchronization with
COM0 to COM7, respectively. If a bit is 1, it is converted to the select voltage, and if it is 0, it is converted to the
deselect voltage. The conversion results are output to the segment pins (SEG4 to SEG38).
When the number of time slices is number other than eight, bits 0 to 3 of each byte in A-pattern area are read in
synchronization with COM0 to COM3, and bits 4 to 7 of each byte in B-pattern area are read in synchronization
with COM0 to COM3, respectively. If a bit is 1, it is converted to the select voltage, and if it is 0, it is converted to
the deselect voltage. The conversion results are output to the segment pins (SEG0 to SEG38).
Check, with the information given above, what combination of front-surface electrodes (corresponding to the
segment signals) and rear-surface electrodes (corresponding to the common signals) forms display patterns in the
LCD display data register, and write the bit data that corresponds to the desired display pattern on a one-to-one
basis.
Remark The mounted segment output pins vary depending on the product.
• 32-pin products: SEG0, SEG4 to SEG6, SEG19 to SEG21, SEG27 to SEG32
• 44-pin products: SEG0 to SEG6, SEG17 to SEG21, SEG25 to SEG34
• 48-pin products: SEG0 to SEG7, SEG16 to SEG21, SEG24 to SEG35
• 52-pin products: SEG0 to SEG8, SEG15 to SEG21, SEG23 to SEG36
• 64-pin products: SEG0 to SEG38