SN8P2318 Series
C-type LCD, RFC 8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 102
Version 1.5
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4x32 LCD DRIVER
10.1 OVERVIEW
The LCD driver density is 4x32 (4 commons and 32 segments, 128 dots) and builds in C-type and R-type structure.
The LCD supports 1/4 duty and 1/2, 1/3 bias LCD panel. The LCD frame rate is 64Hz and clock source is external
32768Hz oscillator crystal or RC type. The C-type only supports 1/3 bias LCD structure. R-type is using external bias
circuit to adjust LCD power and bias voltage. There are 16-pin GPIO shared with SEGs controlled by register. For
difference density LCD panel, users can decides more GPIO pins for application.
10.2 LCD REGISTERS
0CBH
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
LCDM
CPCK1
CPCK0
VLCDCP
PSEG2
PSEG1
PSEG0
BIAS
LCDENB
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
After reset
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Bit [7:6]
CPCK[1:0]:
VLCD charge-pump clock selection.
CPCK[1:0]
Charge-pump Clock
00
32KHz
01
16KHz
10
4KHz
11
1KHz
Note: In general speaking, 1KHz charge-pump clock is enough for most application. Lower charge-pump
clock frequency can save more power consumption. Higher charge-pump clock frequency can provide
stronger V1/V2 driving capability.
Bit 5
VLCDCP:
VLCD charge-pump control bit.
0 = Disable. LCD is R-type.
1 = Enable. LCD is C-type.
Bit [4:2]
PSEG2:
LCD shared pin control bit.
000 = Disable all LCD shared pins
’ GPIO function. The SEG pin number is 32.
001 = Enable P2.0~P2.3 (SEG28~SEG31) GPIO function. The SEG pin number is 28.
010 = Enable P2.0~P2.7 (SEG24~SEG31) GPIO function. The SEG pin number is 24.
011 = Enable P2.0~P2.7 and P3.0~P3.3 (SEG20~31) GPIO function. The SEG pin number is 20.
100 = Enable P2.0~P2.7 and P3.0~P3.7 (SEG16~31) GPIO function. The SEG pin number is 16.
101~111 = Reserved.
Bit 1
BIAS:
LCD bias control bit.
0 = 1/3 bias (C type and R type).
1 = 1/2 bias (R type only).
Bit 0
LCDENB:
LCD control bit.
0 = Disable.
1 = Enable.