HD6473032F Datasheet, PDF (103/572 Pages) Hitachi Semiconductor – Hitachi Microcomputer

5.3 Interrupt Sources
The interrupt sources include external interrupts (NMI, IRQ₀ to IRQ₄) and 21 internal interrupts.
5.3.1 External Interrupts
There are six external interrupts: NMI, and IRQ₀ to IRQ₄. Of these, NMI, IRQ₀, IRQ₁, and IRQ₂
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
number 7.
IRQ₀ to IRQ₄ Interrupts: These interrupts are requested by input signals at pins IRQ₀ to IRQ₄.
The IRQ₀ to IRQ₄ interrupts have the following features.
• ISCR settings can select whether an interrupt is requested by the low level of the input at pins
IRQ₀ to IRQ₄, or by the falling edge.
• IER settings can enable or disable the IRQ₀ to IRQ₄ interrupts. Interrupt priority levels can be
assigned by four bits in IPRA (IPRA7 to IPRA4).
• The status of IRQ₀ to IRQ₄ interrupt requests is indicated in ISR. The ISR flags can be
cleared to 0 by software.
Figure 5-2 shows a block diagram of interrupts IRQ₀ to IRQ₄.
IRQn input
Note: n = 4 to 0
IRQnSC
Edge/level
sense circuit
IRQnE
IRQnF
S
Q
R
Clear signal
IRQn interrupt
request
Figure 5-2 Block Diagram of Interrupts IRQ₀ to IRQ₄
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