Computer Hardware User Manual

MC68HC05RC16 — Rev. 3.0 General Release Specification
MOTOROLA Interrupts 37
General Release Specification — MC68HC05RC16
Section 4. Interrupts
4.1 Contents
4.2 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
4.3 CPU Interrupt Processing. . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
4.4 Reset Interrupt Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
4.5 Software Interrupt (SWI). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
4.6 Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
4.7 External Interrupt (IRQ/Port B Keyscan). . . . . . . . . . . . . . . . . .41
4.8 External Interrupt Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
4.9 Carrier Modulator Transmitter Interrupt (CMT). . . . . . . . . . . . .42
4.10 Core Timer Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
4.2 Introduction
The MCU can be interrupted four different ways:
1. Nonmaskable software interrupt instruction (SWI)
2. External asynchronous interrupt (IRQ/port B keyscan)
3. Internal carrier modulator transmitter interrupt
4. Internal core timer interrupt