HD66420 Datasheet, PDF (36/52 Pages) Hitachi Semiconductor – (RAM-Provided 160 Channel 4-Level Grey Scale Driver for Dot Matrix Graphics LCD)

HD66420
Power On/Off Procedure
Figure 22 shows the procedure for turning the power supply on and off. This procedure must be strictly
followed to prevent incorrect display because the HD66420 incorporates a power supply circuit.
Turn on power (power-on reset)
Set PWR bit to 1 (control register 1)
Boosting starts
Set CNF, ADC, DTY1, DTY0, INC bits according to
the operating mode (control register1 and 2)
Power on
Write data to registers and RAM as required
Set DISP bit to 1 (control register 1)
Clear DISP bit to 0 (control register 1)
Clear PWR bit to 0 (control register 1)
Boosting halts ^{Power off}
Turn off power
Figure 22 Procedure for Turning Power Supply On/Off
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