King Billion Electronics Co., Ltd

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HE847701

HE80000 SERIES

March 26, 2004

Page 17 of 29

V1.03

This specification is subject to change without notice. Please contact sales person for the latest version before use.

As pads of PRT14, PRT15 and PRT17 are shared with LCD segment driver, the function of the pads is

determined by mask options.

PRT170

SEG0

PRT170

PRT171

SEG1

PRT171

PRT172

SEG2

PRT172

PRT173

SEG3

PRT173

PRT174

SEG4

PRT174

PRT175

SEG5

PRT175

PRT176

SEG6

PRT176

PRT177

SEG7

PRT177

PRT150

SEG8

PRT150

PRT151

SEG9

PRT151

PRT152

SEG10

PRT152

PRT153

SEG11

PRT153

PRT154

SEG12

PRT154

PRT155

SEG13

PRT155

PRT156

SEG14

PRT156

PRT157

SEG15

PRT157

PRT140

SEG16

PRT140

PRT141

SEG17

PRT141

PRT142

SEG18

PRT142

PRT143

SEG19

PRT143

PRT144

SEG20

PRT144

PRT145

SEG21

PRT145

PRT146

SEG22

PRT146

PRT147

SEG23

PRT147

LIO17=1

LIO17=0

LIO15=0

LIO15=1

LIO14=0

LIO14=1

Following table is the setting for MO_LIO?[...] and MO_?PP[...] and others related to LCD display

setting and pin assignment features.

MO_LIO?[…] MO_?PP[...]

I/O Port

LCD Pin

0

0

Open-drain output

--

0

1

Push-pull output

--

1

0

--

xx

1

1

--

LCD Display

--: Function not available.

xx: Displayable, but may have abnormal leakage current, do not use.

10. Key Scan Circuit

The built-in 4x20 hardware keyboard scan circuit helps to reduce the pin counts where application

requires large key matrix and high LCD pixel count as well as the firmware effort. As key-scan pins are

shared with LCD segment and PRTC4 ~ PRTC7 pins, it is advisable to put resistors between segment pins

and key matrix to avoid shorting the segment pins when two or more keys in the same row are pressed

simultaneously. Two key can be detected simultaneously and the first detected key code is stored in

KEY0 register and the second in KEY1 register respectively. The key code for each key location is listed

in the following table.

Key Loc SCNI0 SCNI1 SCNI2 SCNI3

SCNO0

0x80

0xA0 0xC0 0xE0

SCNO1

0x81

0xA1 0xC1 0xE1