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CM71-00105-1E FUJITSU MICROELECTRONICS LIMITED 271
FR81 Family
CHAPTER 7 DETAILED EXECUTION INSTRUCTIONS
7.92
7.92 INT (Software Interrupt)
This is a software interrupt instruction. Reads the vector table for the interrupt vector
number u8 to determine the branch destination address, and branches.
● Assembler Format
INT #u8
Vector numbers 9 to 13, 64 and 65 are used by emulators for debugging interrupts and therefore the
corresponding numbers "INT #9" to "INT #13", "INT #64", "INT #65" should not be used in user
programs.
● Operation
SSP-4 → SSP
PS → (SSP)
SSP-4 → SSP
PC+2 → (SSP)
"0" → CCR:I
"0" → CCR:S
(TBR+3FC
H
-u8 × 4) → PC
Stores the values of the program counter (PC) and program status (PS) to the stack indicated by the system
stack pointer (SSP) for interrupt processing. Writes "0" to the S flag in the condition code register (CCR),
and uses the SSP as the stack pointer for following steps. Writes "0" to the I flag (interrupt enable flag) in
the CCR to disable external interrupts. Reads the vector table for the interrupt vector number u8 to
determine the branch destination address, and branches.
● Flag Change
N, Z, V, C: Unchanged.
S, I: Cleared.
● Classification
Non-Delayed Branching instruction
SIN Z V C
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