RL78/G1P
CHAPTER 15 INTERRUPT FUNCTIONS
R01UH0895EJ0100 Rev.1.00
574
Nov 29, 2019
CHAPTER 15 INTERRUPT FUNCTIONS
The interrupt function switches the program execution to other processing. When the branch processing is finished, the
program returns to the interrupted processing.
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 two priority groups by setting the
priority specification flag registers (PR00L, PR00H, PR01L, PR10L, PR10H, PR11L).
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 default priority of vectored interrupt servicing. Default priority, see
Table 15-1
.
A standby release signal is generated and STOP, HALT, and SNOOZE modes are released.
External interrupt requests and internal interrupt requests are provided as maskable interrupts.
External: 6, Internal: 12
(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
Interrupt sources include maskable interrupts and software interrupts. In addition, they also have up to seven reset
sources (see
Table 15-1
). The vector codes that store the program start address when branching due to the generation of
a reset or various interrupt requests are two bytes each, so interrupts jump to a 64 K address of 00000H to 0FFFFH.