UPD78F1502AGK-GAK-AX Datasheet, PDF (697/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 16 LCD CONTROLLER/DRIVER
(2) Segment signals
The segment signals correspond to the LCD display data memory (refer to 16.4 LCD Display Data Memory).
When the number of time slices is eight, bits 0 to 7 of each byte 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 SEG53).
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 SEG53).
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 memory, and write the bit data that corresponds to the desired display pattern on a one-to-
one basis.
LCD display data memory bits 1 to 3, bits 2 and 3, bit 3, and F0400H to F0403H are not used for LCD display in
the static display, two-time slot, three-time slot, and eight-time slot modes, respectively. So these bits can be
used for purposes other than display.
Remark The mounted segment output pins vary depending on the product.
• 78K0R/LF3: SEG0 to SEG30
• 78K0R/LG3: SEG0 to SEG39
• 78K0R/LH3: SEG0 to SEG53
R01UH0004EJ0501 Rev.5.01
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Jun 20, 2011