SN32F280 Series
32-Bit Cortex-M0 Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 196
Version 1.1
17.5 LCD BIAS GENERATOR
The LCD bias generator include LCD contrast control and 1/3 bias control. The LCD contrast control is used to set the
voltage of VLCD. There are 16-stage VLCD voltage from VDD to VDD*0.5 and is controlled by VLCD[3:0] bits. The 1/3
bias control circuit has three resistances (R
LCD
) for difference VLCD controlled by LCDBIA[2:0] bits. The R
LCD
is from
17.65K
Ω to 300KΩ. The final 4-level LCD bias voltage source is VLCD/V2/V1/GND and supply to LCD COM and SEG
pins. When the static mode is active (LSTC=1), both LCD contrast control and 1/3 bias control will be turned off.
VLCD[3:0]
VLCD
V2
V1
R
LCD
R
LCD
R
LCD
GND
M
U
X
R
R
R
R
...
...
VDD
17.6 LCD INTERRUPT
The FCIF bit will be set after one LCD frame finishes and will triggers LCD interrupt when FCIE = 1.
LCD frame 1
LCD frame 2
LCD frame 3
LCD frame 4
LCDEN = 1
FCIF = 1
FCIF = 1
FCIF = 1
FCIF = 1
Frame end
Frame end
Frame end
Frame end