Datasheet

Table Of Contents
Section 5 Interrupt Controller
Page 92 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
5.4 Interrupt Sources
5.4.1 External Interrupts
There are eight external interrupts: NMI, IRQ7, and IRQ5 to IRQ0. These interrupts can be used
to restore this LSI from software standby mode. IRQ6 is an interrupt only for the on-chip USB.
However, IRQ6 is functionally same as IRQ7 restore this LSI from software standby mode. IRQ6
is functionally same as IRQ7 and IRQ5 to IRQ0.
NMI Interrupt: NMI is the highest-priority interrupt, and is always accepted by the CPU
regardless of the interrupt control mode or the status of the CPU interrupt mask bits. The NMIEG
bit in SYSCR can be used to select whether an interrupt is requested at a rising edge or a falling
edge on the NMI pin.
IRQ7 to IRQ0 Interrupts: Interrupts IRQ7 to IRQ0 are requested by an input signal at pins IRQ7
to IRQ0. Interrupts IRQ7 to IRQ0 have the following features:
Using ISCR, it is possible to select whether an interrupt is generated by a low level, falling
edge, rising edge, or both edges, at pins IRQ7 to IRQ0
Enabling or disabling of interrupt requests IRQ7 to IRQ0 can be selected with IER.
The interrupt priority level can be set with IPR.
The status of interrupt requests IRQ7 to IRQ0 is indicated in ISR. ISR flags can be cleared to 0
by software.
A block diagram of IRQn interrupts is shown in figure 5.2.
IRQnE
IRQnF
S
R
Q
IRQn interrupt
request
Clear signal
Edge/level
detection circuit
IRQnSCA, IRQnSCB
IRQn input
Note: n = 7 to 0
Figure 5.2 Block Diagram of IRQn Interrupts