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CHAPTER 18 LCD CONTROLLER/DRIVER
User’s Manual U15798EJ2V0UD
Cautions 1. Set the LCDON, SCOC, and VLCON bits in the following sequence:
•
To display LCD while LCD booster circuit is stopped
(1) Set VLCON to 1. All the segment and common pins are in the GND output mode
(SCOC = 0).
↓
(2) Set VLCON to 1 and wait 500 ms or longer with software.
↓
(3) Set SCOC to 1. All the segment and common pins output an unselect waveform and
are in unselect display mode.
↓
(4) Set LCDON to 1. The value of the display RAM is reflected on the segment output
waveform, and all segment and common pins are in select display mode.
•
To stop LCD booster circuit while LCD displays
(1) Clear LCDON to 0. All the segment and common pins are in unselect display mode.
↓
(2) Clear SCOC to 0. All the segment and common pins are in GND output mode.
↓
(3) Clear VLCON to 0. The LCD booster circuit stops.
2. The blinking cycle is generated using the interval time of the watch timer (0.5 s at 32.768
kHz). When the blinking function is not used (BLON = 0), the LCD lights or extinguishes
depending on the setting of the display RAM, as shown in Figure 18-3. When the blinking
function is used (BLON = 1), the LCD lights or extinguishes depending on the status of the
internal blinking clock signal (set value of BLSEL), i.e., it lights if the internal blinking clock
signal is “1” and extinguishes if the signal is “0”.
Figure 18-3. Blinking Function
3. When using the blinking function, the LCD does not blink even if the data is rewritten while
the LCD is in the extinguishing cycle (0.5 s or 1.0 s), unless the LCD moves to the lighting
cycle.
Extin-
guishes
Lights
Display RAM
0.5 s
0.5 s
0.5 s
0.5 s
Watch timer
Interrupt
internal blinking
Clock signal
display RAM
BLON
Display status
Internal blinking clock signal
Extinguishes
Lights
Содержание mPD780344 Series
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