Section 5 Interrupt Controller; Overview; Features; Interrupt Controller - Hitachi H8S/2646 Hardware Manual

5.1

Overview

5.1.1

Features

The H8S/2646 Series controls interrupts by means of an interrupt controller. The interrupt
controller has the following features:
• Two interrupt control modes
 Any of two interrupt control modes can be set by means of the INTM1 and INTM0 bits in
the system control register (SYSCR).
• Priorities settable with IPR
 An interrupt priority register (IPR) is provided for setting interrupt priorities. Eight priority
levels can be set for each module for all interrupts except NMI.
 NMI is assigned the highest priority level of 8, and can be accepted at all times.
• Independent vector addresses
 All interrupt sources are assigned independent vector addresses, making it unnecessary for
the source to be identified in the interrupt handling routine.
• Seven external interrupts
 NMI is the highest-priority interrupt, and is accepted at all times. Rising edge or falling
edge can be selected for NMI.
 Falling edge, rising edge, or both edge detection, or level sensing, can be selected for IRQ5
to IRQ0.
• DTC control
 DTC activation is performed by means of interrupts.

Section 5 Interrupt Controller

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