King Billion Electronics Co., Ltd

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HE847701

HE80000 SERIES

March 26, 2004

Page 14 of 29

V1.03

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

7.1. LCDC Control register

The gray scale of the LCD driver can be adjusted by GRAY field of LCD. The LCD panel can be blanked

by setting the BLANK field of LCDC register. LCD driver can be totally turned off by clearing LCDE bit

of LCDC.

LCDC

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

Field

-

-

-

GRAY

BLANK LCDE

Reset

-

-

-

-

-

-

1

0

Field

Value Function

GRAY

000

LCD is darkest.

111

LCD is lightest.

BLANK

0

normal display

1

LCD display blanked. The COM signals of LCD driver output inactive levels

(LVL4 and LVL1) while SEG signals output normal display patterns.

LCDE

0

LCD driver disabled, LCD driver has no output signal.

1

LCD driver Enabled

Please note that LCD driver must be turned off before the MCU goes into sleep mode. In other words,

user must clear the bit 0 (LCDE bit) of LCDC to turn off LCD driving circuit before setting bit6 of OP1

to enter sleep mode. Large current might happen if the procedure is not followed.

Please note that LCD driver uses slow clock as clock source. The LCD display would not display

normally if it worked in Fast clock only mode as the LCD refresh action would be too fast.

8. Oscillators

The MCU is equipped with two clock sources with a variety of selections on the types of oscillators to

choose from. So that system designer can select oscillator types based on the cost target, timing accuracy

requirements etc. Crystal, Resonator or the RC oscillator can be used as fast clock source, components

should be placed as close to the pins as possible. The type of oscillator used is selected by mask option

MO_FXTAL.

MO_FXTAL Fast clock type

0

RC Oscillator.

1

Crystal Oscillator.

FXI

FXI

FXO

R

22p

22p

3579545Hz

Crystal Osc.

RC Osc.