
NT7501
24
18. Static Indicator
This command turns on or off the static drive indicators. The indicator display is controlled by this command only, and it is
not affected by the other display control commands.
Either the FR or FRS terminal is connected to either of the static indicator LCD drive electrodes, and the remaining terminal
is connected to another electrode. When the indicator is turned on, the static drive operates and the indicator blinks at an
interval of approximately one second. This pattern separation between indicator electrodes and dynamic drive electrodes
is recommended. A closer pattern may cause a LCD and electrode deterioration.
A0
E
RD
W
R
WR
0
D7
D6
D5
D4
D3
D2
D1
D0
0
1
1
0
1
0
1
1
0
D
D 0: Static indicator OFF
1: Static indicator ON
19. Power Save (Compound Command)
When all displays are turned on during display off, the Power Save command is issued to greatly reduce the current
consumption.
If the static indicators are off, the Power Save command sleeps the system. If on, this command stands by the system.
Release the Sleep mode using the Power Save OFF command (Display ON command or Entire Display OFF command).
Static Indicator OFF
Static Indicator ON
Power Save
(Display OFF and Entire Display ON)
(Sleep mode)
(Standby mode)
Power Save OFF
(Display ON or Entire Displays OFF )
Static Indicator ON
(Sleep mode released)
(Standby mode released)
Sleep mode
This mode stops every operation of the LCD display system, and can reduce current consumption to a nearly static current
value if no access is made from the microprocessor. The internal status in the sleep mode is as follows:
(1) Stops the oscillator circuit and LCD power supply circuit.
(2) Stops the LCD drive and outputs the V
SS
level as the segment/common driver output.
(3) Holds the display data and operation mode provided before the start of the sleep mode.
(4) The MPU can access the built-in display RAM.
Standby mode
Stops the operation of the duty LCD display system and turns on only the static drive system to reduce current
consumption to the minimum level required for static drive.
The ON operation of the static drive system indicates that the NT7501 is in the standby mode. The internal status in the
standby mode is as follows:
(1) Stops the LCD power supply circuit.
(2) Stops the LCD drive and outputs the V
SS
level as the segment/common driver output. However, the static drive
system operates.
(3) Holds the display data and operation mode provided before the start of the standby mode.
(4) The MPU can access to the built-in display RAM.
When the RESET command is issued in the standby mode, the sleep mode is set.