Datasheet
87
Section 5 Exception Processing
5.1 Overview
5.1.1 Types of Exception Processing and Priority
Exception processing is started by four sources: resets, address errors, interrupts and instructions
and have the priority shown in table 5.1. When several exception processing sources occur at once,
they are processed according to the priority shown.
Table 5.1 Types of Exception Processing and Priority Order
Exception Source Priority
Reset Power-on reset High
Manual reset
Address CPU address error
error
DMAC/DTC address error
Interrupt NMI
User break
IRQ
On-chip peripheral modules:
• Direct memory access controller (DMAC)
• Multifunction timer/pulse unit (MTU)
• Serial communications interface (SCI)
• A/D converter (A/D)
*
3
• Data transfer controller (DTC)
• Compare match timer (CMT)
• Watchdog timer (WDT)
• Bus state controller (BSC)
• Port output enable control section
Instructions Trap instruction (TRAPA instruction)
General illegal instructions (undefined code)
Illegal slot instructions (undefined code placed directly after a delay branch
instruction
*
1
or instructions that rewrite the PC
*
2
)
Low
Notes: *1 Delayed branch instructions: JMP, JSR, BRA, BSR, RTS, RTE, BF/S, BT/S, BSRF,
BRAF.
*2 Instructions that rewrite the PC: JMP, JSR, BRA, BSR, RTS, RTE, BT, BF, TRAPA,
BF/S, BT/S, BSRF, BRAF.
*3 A mask products: A/D0, A/D1.