HD6433682 ETC, HD6433682 Datasheet - Page 77

• Manufacturer Part Number: HD6433682
• Description: Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Tiny Series
• Manufacturer: ETC

Exception handling may be caused by a reset, a trap instruction (TRAPA), or interrupts.
A reset has the highest exception priority. Exception handling starts as soon as the reset is cleared
by the RES pin. The chip is also reset when the watchdog timer overflows, and exception handling
starts. Exception handling is the same as exception handling by the RES pin.
Exception handling starts when a trap instruction (TRAPA) is executed. The TRAPA instruction
generates a vector address corresponding to a vector number from 0 to 3, as specified in the
instruction code. Exception handling can be executed at all times in the program execution state,
regardless of the setting of the I bit in CCR.
External interrupts other than NMI and internal interrupts other than address break are masked by
the I bit in CCR, and kept masked while the I bit is set to 1. Exception handling starts when the
current instruction or exception handling ends, if an interrupt request has been issued.
Reset
Trap Instruction
Interrupts
Section 3 Exception Handling
Rev. 3.00, 05/03, page 47 of 472