Chapter 19 Interrupt Functions; Interrupt Function Types; Interrupt Sources And Configuration - NEC 78K0 Series User Manual

19.1 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, PR1H).
Multiple interrupt servicing can be applied to low-priority interrupts when high-priority interrupts are generated. If
two or more interrupt requests, each having the same priority, are simultaneously generated, then they are
processed according to the priority of vectored interrupt servicing. For the priority order, see Table 19-1.
A standby release signal is generated and STOP and HALT modes are released.
External interrupt requests and internal interrupt requests are provided as maskable interrupts.
• µ
PD78F0531, 78F0532, 78F0533
External: 9, internal: 16
µ
•
PD78F0534, 78F0535, 78F0536, 78F0537, 78F0537D
External: 9, internal: 19
(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.

19.2 Interrupt Sources and Configuration

µ
The PD78F0531, 78F0532, and 78F0533 have a total of 26 interrupt sources, and the
78F0536, 78F0537, and 78F0537D have a total of 29 interrupt sources, including maskable interrupts and software
interrupts. In addition, they also have up to four reset sources (see Table 19-1).
486

CHAPTER 19 INTERRUPT FUNCTIONS

Preliminary User's Manual U17260EJ3V1UD
µ
PD78F0534, 78F0535,