w925e625 ETC-unknow, w925e625 Datasheet - Page 51

• Manufacturer Part Number: w925e625
• Description: 8-bit Cid Microcontroller
• Manufacturer: ETC-unknow

6.15 LCD
1792 dots: 56 Segments x 32 Common, 1/5 bias
An internal voltage pump is enable/disable by option code. The LCD on/off is controlled by bit LCDON
(SCON1.6). If the voltage pump is enable, when LCDON is high to pump voltage and the LCD
waveform is output to LCD pins according the LCD memory, when LCDON is low to turn off the
voltage pump. The voltage of internal regulator is the base voltage of the voltage pump which 5 times
of the base voltage. The output voltage of the regulator is tunable by 4 bits in regulator voltage control
register (REGVC). When REGVC is equal to 0AH, the output voltage is 1.0V. The higher value of
REGVC the lower voltage output of regulator. The adjustable voltage range is about from 0.72V to
1.48V . Accordingly, the LCD contrast is controlled by the value of REGVC. The variation of the
voltage depends on the V
LCD Frequency
The alternating frequency of the LCD can be set as 16Hz, 32Hz, 64Hz and 128Hz that are determined
by 2 bits of option code. Structure of the LCD alternating frequency (F
Fw = 32.768 KHz, the LCD frequency is shown in the table below.
No
Loading(3V)
No
Loading(5V)
With LCD
Loading(3v)
With LCD
Loading(5v)
Regvc
1.497 1.4464 1.3941 1.3426 1.2899 1.238 1.186 1.1352 1.081 1.029 0.976 0.924 0.869 0.815 0.762 0.7112
1.500 1.449 1.397
1.484 1.433 1.381
1.46
Sub-oscillator clock
00
1.41
01
1.36
02
DD
Figure 6-14 LCD alternating frequency (FLCD) circuit diagram
. Following is the table of REGVC vs. regulator voltage.
1.345
1.330
32K
1.31
03
1.292 1.241 1.188 1.137 1.083 1.031 0.978 0.925 0.87 0.816 0.763 0.712
1.278 1.227 1.176 1.125 1.072 1.024 0.975 0.926 0.874 0.825 0.773 0.723
Q1
1.26
04
16K
1.21 1.16
Q2
05
8K
06
Q3
- 51 -
option code
4K
2 bits of
1.11
07
Q4
00
01
10
11
2K
1.05
08
M
u
x
09
1
Publication Release Date: July 4, 2005
LCD
0ah 0bh 0ch 0dh 0eh
0.95
Waveform
LCD COM
Generator
) is shown in Figure 6-14.
0.9
W925E/C625
0.85 0.80 0.75
F
LCD
Revision A10
0.71
0fh