HT95LXXX
LCD Driver
The LCD driver can directly drive an LCD panel with 1/8 duty and 1/4 bias or with 1/16 duty and 1/5 bias, this function is
selected by the flag VBIAS. The frame of this LCD driver may select a 64Hz or 128Hz by flag FRAME.
LCD driver uses the voltage of the VLCD pin as the power source. To adjust the view angle, the programmer can select
the real LCD power by the flags VCON0 and VCON1. The flag LCDON is used to turn On/Off the LCD display. Note that
the VLCD voltage must equal or be less than VDD.
Segment/Common to I/O Selection
For the flexible purpose, some of the LCD COMMON and SEGMENT pins are shared with the input/output port.
Both of the HT95L400/40P and HT95L300/30P provide 12 pins to be selected to SEGMENT output pins or I/O pins.
HT95L200/20P provides 8 pins to be selected for COMMON output pins or I/O pins. Both of the HT95L100/10P and
HT95L000/00P provide 4 pins to be selected for SEGMENT output pins or I/O pins.
All of the HT95L400/40P, HT95L300/30P and HT95L200/20P provide the LCD COMMON output pins for 8 COMMON
or 16 COMMON. The description of the relation between segment pins, common pins and I/O pins are shown on the
below.
Register Label Bits R/W
Function
Supported for HT95L400/40P, HT95L300/30P, HT95L200/20P, HT95L100/10P
LCD frame selection
FRAME
0
RW 0: LCD frame is 64Hz
1: LCD frame is 128Hz
The frame frequency is fixed to 64Hz for HT95L100/10P and HT95L000/00P
Supported for HT95L400/40P, HT95L300/30P, HT95L200/20P
LCD BIAS selection
0: select 1/16 duty and 1/5 bias, COM15~COM0 are available
1: select 1/8 duty and 1/4 bias, only COM15~COM8 are available
VBIAS
1
RW
When the 8 COM is selected
HT95L400/40P: COM7~COM0 will be optioned to unused pins
HT95L300/30P: COM7~COM0 will be optioned to unused pins
HT95L200/20P: COM7~COM0 are disabled, PD7~PD0 are available
Supported for HT95L400/40P, HT95L300/30P, HT95L200/20P, HT95L100/10P
Low battery detection switch
RW
LCDC
(2DH)
LBEN
¾
2
3
4
0: disable the low battery detection
1: enable the low battery detection
RO
Unused bit, read as ²0²
Supported for HT95L400/40P, HT95L300/30P, HT95L200/20P, HT95L100/10P
Low battery detection flag
LBFG
ROS
1: LBIN pin voltage is less than 1.15V
0: LBIN pin voltage is not less than 1.15V
LCD contrast adjusting
Bit6,5=00: LCD voltage supply is 0.66´VLCD
VCON0
VCON1
5
6
RW Bit6,5=10: LCD voltage supply is 0.82´VLCD
Bit6,5=01: LCD voltage supply is 0.93´VLCD
Bit6,5=11: LCD voltage supply is 1.00´VLCD
1: Turn on the LCD display
RW
LCDON
7
0: Turn off the LCD display
Rev. 1.20
28
May 26, 2004
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
