Datasheet

Section 3 Exception Handling
Rev. 3.00 Mar. 15, 2006 Page 55 of 526
REJ09B0060-0300
3.4 Interrupt Exception Handling
3.4.1 External Interrupts
As the external interrupts, there are NMI, IRQ3 to IRQ0, and WKP5 to WKP0 interrupts.
NMI Interrupt:
NMI interrupt is requested by input signal edge to pin NMI. This interrupt is detected by either
rising edge sensing or falling edge sensing, depending on the setting of bit NMIEG in IEGR1.
NMI is the highest-priority interrupt, and can always be accepted without depending on the I bit
value in CCR.
IRQ3 to IRQ0 Interrupts:
IRQ3 to IRQ0 interrupts are requested by input signals to pins IRQ3 to IRQ0. These four
interrupts are given different vector addresses, and are detected individually by either rising edge
sensing or falling edge sensing, depending on the settings of bits IEG3 to IEG0 in IEGR1.
When pins IRQ3 to IRQ0 are designated for interrupt input in PMR1 and the designated signal
edge is input, the corresponding bit in IRR1 is set to 1, requesting the CPU of an interrupt. These
interrupts can be masked by setting bits IEN3 to IEN0 in IENR1.