Key Input Interrupt - Renesas R8C/18 Series Hardware Manual

R8C/18 Group, R8C/19 Group
12.3

Key Input Interrupt

A key input interrupt request is generated by one of the input edges of pins K10 to K13. The key input
interrupt can be used as a key-on wake-up function to exit wait or stop mode.
The KIiEN (i = 0 to 3) bit in the KIEN register can select whether or not the pins are used as KIi input.
The KIiPL bit in the KIEN register can select the input polarity.
When "L" is input to the KIi pin, which sets the KIiPL bit to 0 (falling edge), input to the other pins K10 to
K13 is not detected as interrupts. Also, when "H" is input to the KIi pin, which sets the KIiPL bit to 1
(rising edge), input to the other pins K10 to K13 is not detected as interrupts.
Figure 12.17 shows a Block Diagram of Key Input Interrupt.
Pull-up
transistor
KI3
Pull-up
transistor
KI2
Pull-up
transistor
KI1
Pull-up
transistor
KI0
Figure 12.17 Block Diagram of Key Input Interrupt
Rev.1.30 Apr 14, 2006
REJ09B0222-0130
PU02 bit in PUR0 register
PD1_3 bit in PD1 register
KI3EN bit
KI3PL = 0
KI3PL = 1
KI2EN bit
KI2PL = 0
KI2PL = 1
KI1EN bit
KI1PL = 0
KI1PL = 1
KI0EN bit
KI0PL = 0
KI0PL = 1
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KUPIC register
PD1_3 bit
PD1_2 bit
Interrupt control
PD1_1 bit
KI0EN, KI1EN, KI2EN, KI3EN,
KI0PL, KI1PL, KI2PL, KI3PL: Bits in KIEN register
PD1_0 bit
PD1_0, PD1_1, PD1_2, PD1_3: Bits in PD1 register
12. Interrupts
Key input interrupt
circuit
request