Interrupt Sources; External Interrupts - Hitachi H8/3062 Hardware Manual

Single-chip microcomputer

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Interrupt Sources

The interrupt sources include external interrupts (NMI, IRQ

There are seven external interrupts: NMI, and IRQ

can be used to exit software standby mode.

NMI: NMI is the highest-priority interrupt and is always accepted, regardless of the states of the

I and UI bits in CCR*. The NMIEG bit in SYSCR selects whether an interrupt is requested by the

rising or falling edge of the input at the NMI pin. NMI interrupt exception handling has vector

Note: * In the versions with on-chip flash memory, NMI input is sometimes disabled. For details

see 17.6.4, NMI Input Disable Conditions.

Interrupts: These interrupts are requested by input signals at pins IRQ

interrupts have the following features.

• ISCR settings can select whether an interrupt is requested by the low level of the input at pins

, or by the falling edge.

• IER settings can enable or disable the IRQ

assigned by four bits in IPRA (IPRA7 to IPRA4).

• The status of IRQ

to 0 by software.

Figure 5.2 shows a block diagram of interrupts IRQ

Note: n = 5 to 0

interrupt requests is indicated in ISR. The ISR flags can be cleared

sense circuit

Figure 5.2 Block Diagram of Interrupts IRQ

. Of these, NMI, IRQ

interrupts. Interrupt priority levels can be

Clear signal

) and 27 internal interrupts.

IRQn interrupt