SN8P2318 Series
C-type LCD, RFC 8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 104
Version 1.5
10.4 R-TYPE LCD MODE
In R-type mode, LCD power (VLCD) is connected with internal VDD. V1, V2 bias voltage is controlled by external
resistor. The bias resistors determine LCD V1, V2 bias voltage and LCD driver current. Too much current makes LCD
panel to bring remnant images. In normal condition, the suggestion of the external bias resistor’s value is 100Kohm. In
R-
type LCD mode, the VLCDCP bit of VLCD register must be “0”.
LCD Bias
VLCD
V2
V1
1/3 Bias (Bias=0)
VDD
2/3*VDD
1/3*VDD
1/2 Bias (Bias=1)
VDD
1/2*VDD
1/2*VDD
MCU
VLCD
V2
V1
VSS
100Kohm
100Kohm
100Kohm
C+
C-
1/3 bias, 1/4 duty, R-type LCD Circuit.
VSS
0.1uF
0.1uF
0.1uF
MCU
VLCD
V2
V1
VSS
100Kohm
100Kohm
C+
C-
1/2 bias, 1/4 duty, R-type LCD Circuit.
VSS
0.1uF
0.1uF
VLCD Power Source
VLCD Power Source
In R-type mode, C+/C-
don’t connect any devices.
1/2 bias, V2 connects to V1.
The 0.1uF capacitors of VLCD/V1/V2 pins are necessary for power stable.
Note: Note: The VLCD voltage source is from external power source depended on LCD panel power level,
and VLCD voltage level
can’t be larger than MCU’s Vdd.
Example : The configuration of R-type LCD mode.
; Set C-type LCD.
MOV
A, #000mmmn0B
;
“n” selects bias.
B0MOV
LCDM
;
“mmm” controls P2/P3 LCD shared pins.
; Enable LCD driver.
B0BSET
FLCDENB
; Enable LCD driver..
; LCD picture process.
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