W79E217A Datasheet, PDF (179/207 Pages) Winbond – 8-bit Microcontroller

Preliminary W79E217A Data Sheet
20.4 LCD Option Bits
There are two option bits for LCD, LCD [1:0] for selection of LCD Segment pin as per the table below.
When option bit LCD [1:0] = 00 the entire Segment pins are active and P5, P6 & P7 cannot work as
general purpose I/O. When LCD [1:0] = 01, P6 & P7 can work as general purpose I/O but only
Seg15~Seg0 can be use for LCD display. Where as LCD [1:0] = 10, only P7 can work as general
purpose I/O and Seg23~0 is use for LCD display. When LCD [1:0] = 11 only Seg9~0 can be use for
LCD display. See section 24 for location of these bits.
LCD1
0
0
1
1
LCD0
0
1
0
1
ACTIVE
Seg31~0
P7 & P6 & Seg15~0
P7 & Seg23~0
GPIO Pins (P5, P6, P7)
20.5 LCD Display
Each number is control by 4 common pins and 2 segment pins. To display a number, data is written
into the LCDDATA to display out into the LCD panel. There are total of 16 LCD characters pointed by
LCDPT.
Figure 20-11: LCD Segment and Com mapping
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Publication Release Date: December 14, 2007
Revision A3.0