st2032a Sitronix Technology Corporation, st2032a Datasheet - Page 33

• Manufacturer Part Number: st2032a
• Description: 8 Bit Microcontroller With 32k Bytes Rom
• Manufacturer: Sitronix Technology Corporation

1
ST2032A is capable of driving one 1/16 duty, 1/5 bias LCD
panel of segment number from 20 to 36(up to 576 dots).
LCD block includes display frame buffer ($1000~ $10A3)
for storing display data, 16 common and 20 segment
dedicated drives. The rest 16 segment drives are shared
with two I/O ports, Port-B/C. Data in frame buffer is
undefined after power on, so correct frame data should be
filled in before turn on display. One double DC-DC
converter is equipped for higher LCD voltage, and is
15.1 LCD Waveform
LCD driving waveform is based on the display data and the
alternation signal, which toggles every one frame. The
related output voltage levels are shown below.
Ver 2.4
1
VP
V1
V2
V3
V4
V5
VP
V1
V2
V3
V4
V5
5
5
.
.
L
L
C
C
D
D
Common
Segment
Driver
Non-selected
Non-selected
Selected
Selected
Mode
FIGURE 15-2 LCD Common Waveform
FIGURE 15-1 LCD Segment Waveform
TABLE 15-1 Driver Output Levels
Alternation
H
H
H
H
L
L
L
L
33/54
controlled by LPWR (LCTL[7]) for on/off. The LCD power
should be turned on before setting display on, and should
be turned off after setting display off. Both SYSCK and
OSCX can be chose as LCD clock source, therefore the
display can still works after power down. There are two
frame rate options, 64Hz and 85Hz, for each different clock
sources. In case of 64Hz frame rate, 8-level driving strength
and 12-level contrast are adjustable by software for
different panel size and LC voltage.
FIGURE 15-1/ FIGURE 15-2 shows the segment and
common waveforms.
Display data output level
GND(V5)
GND(V5)
VP
VP
V1
V4
V2
V3
ST2032A
9/13/07