Datasheet

78K0/Ix2 CHAPTER 18 INTERRUPT FUNCTIONS
R01UH0010EJ0500 Rev.5.00 571
Feb 28, 2012
CHAPTER 18 INTERRUPT FUNCTIONS
78K0/IY2 78K0/IA2 78K0/IB2 Item
16 pins 20 pins 30 pins 32 pins
External 7 7 9 8 Maskable interrupts
internal 8 12 13 13
18.1 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, refer to Table 18-1.
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.
(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.
18.2 Interrupt Sources and Configuration
The interrupt sources consist of maskable interrupts and software interrupts. In addition, they also have up to four
reset sources (refer to Table 18-1).