Software

AN3245

14/19

Doc ID 17747 Rev 1

//Set scan count, no dedicated keys

WriteRegister(INT_EN_MASK_LOW,0x06);

//Enable KPC FIFO overflow and KPC Interrupt

ReadRegister(INT_STA_LOW);

//Clear Interrupt Status register

WriteRegister(INT_CTRL_LOW,0x01);

//Active Low, Level Interrupt, Enable Global Interrupt

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GPIO initialization (e.g. GPIO low to output, GPIO MID to input)

WriteRegister(SYS_CTRL, 0x80);//Issue SW reset

WriteRegister(GPIO_SET_DIR_LOW,0xFF); //Set port to OUTPUT

WriteRegister(GPIO_SET_DIR_MID,0x00); //Set port to INPUT

WriteRegister(GPIO_SET_DIR_HIGH,0x03); //IO 16/17 UNUSED,Set to

OUTPUT

WriteRegister(INT_EN_MASK_LOW,0x08); //Enable GPIO Interrupt

WriteRegister(INT_EN_GPIO_MASK_MID,0xFF); //Enable 8-15 Input

Interrupt

ReadRegister(INT_STA_GPIO);

//Clear all status in GPIO status register

ReadRegister (INT_STA_LOW);

//Clear Interrupt Status register

WriteRegister(INT_CTRL_LOW,0x01);

//Active Low, Level Interrupt, Enable Global Interrupt

●

Hotkey initialization (e.g. Setting GPIO15 as hotkey)

WriteRegister(GPIO_SET_DIR_MSB,0x80); //Set GPIO15 to INPUT

WriteRegister(GPIO_SET_RE_MSB,0x80);

//Set GPIO15 as RISING EDGE trigger

WriteRegister(INT_CTRL,0x01);

//Active Low, Level Interrupt, Enable Global Interrupt

2.2.2

Interrupt handling

The following is a sample for the device interrupt/hotkey serving routine based on standard

implementation. It is necessary to ensure that the host and STMPE1801 interrupt type

(active high/low and level/edge detect) are consistent.

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Interrupt service routine

ON_INTERRUPT

INT_STATUS = ReadRegister(INT_STA_LOW); //Read Interrupt Status

register

// GPIO Interrupt