Chapter 15 Interrupt Functions; Interrupt Function Types; Interrupt Sources And Configuration - NEC 78K0 User Manual

15.1 Interrupt Function Types

The following two types of interrupt functions are used.
(1) Maskable interrupts
These interrupts undergo mask control. Maskable interrupts can be divided into a high interrupt priority group
and a low interrupt priority group by setting the priority specification flag registers (PR0L, PR0H, PR1L).
Multiple interrupt servicing can be applied to low-priority interrupts when high-priority interrupts are generated. If
two or more interrupts with the same priority are generated simultaneously, each interrupt is serviced according to
its predetermined priority (see Table 15-1).
A standby release signal is generated and STOP and HALT modes are released.
Seven external interrupt requests and 15 internal interrupt requests are provided as maskable interrupts.
(2) Software interrupt
This is a vectored interrupt generated by executing the BRK instruction. It is acknowledged even when interrupts
are disabled. The software interrupt does not undergo interrupt priority control.

15.2 Interrupt Sources and Configuration

A total of 23 interrupt sources exist for maskable and software interrupts (see Table 15-1).

CHAPTER 15 INTERRUPT FUNCTIONS

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