HD66724 Datasheet, PDF (63/117 Pages) Hitachi Semiconductor – (Graphics LCD Controller/Driver with Key Scan Function)

Turn off LCD power (AMP = 0)
Enable interrupts (IRE = 1)
Set sleep mode (SLP = 1)
Sleep mode
Key input (key → HD66724/5)
Generate interrupt (HD66724/5 → MPU)
Mask interrupts (IRE = 0)
Read key-scanned data
HD66724/HD66725
Turn off LCD power (AMP = 0)
Set standby mode (STB = 1)
Standby mode
Enable interrupts (IRE = 1)
Key input (key → HD66724/5)
Generate interrupt (HD66724/5 →MPU)
Start R-C oscillator (HD66724/5)
Wait 10 ms or longer (MPU)
Mask interrupts (IRE = 0)
Clear standby mode (STB = 0)
Read key-scanned data
Figure 31 Key Scan Interrupt Processing Flow in Sleep and Standby Modes
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