HD66724 Datasheet, PDF (98/117 Pages) Hitachi Semiconductor – (Graphics LCD Controller/Driver with Key Scan Function)

HD66724/HD66725
Sleep Mode
Setting the sleep mode bit (SLP) to 1 puts the HD66724/HD66725 in the sleep mode, where the device
stops all internal display operations except for key scan operations, thus reducing current consumption.
Specifically, LCD drive is completely halted. Here, all the SEG (SEG1 to SEG72 (96)) and COM (COM1
to COM24, COMS1/2) pins output the GND level, resulting in no display. If the AMP bit is set to 0 in the
sleep mode, the LCD drive power supply can be turned off, reducing the total current consumption of the
LCD module.
The key scan circuit operates normally in the sleep mode, thus allowing normal key scan and key scan
interrupt generation. For details, refer to the Key Scan Control section and Key Scan Interrupt (Wake-up
Function) section.
Table 48 Comparison of Sleep Mode and Standby Mode
Function
Character display
Segment display
R-C oscillation
Key scan
Sleep Mode (SLP = 1)
Turned off
Turned off
Operates normally
Can operate normally
Standby Mode (STB = 1)
Turned off
Turned off
Halted
Halted but IRQ* can be generated
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