Fujitsu MB90480 Series Hardware Manual page 88

CHAPTER 3 INTERRUPT
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Software interrupt operation
Figure 3.5-1 shows the operation starting from software interrupt generation until interrupt
processing completion.
Internal data bus
PS : Processor status
I : Interrupt enable flag
S : Stack flag
IR : Instruction register
1. Run a software interrupt instruction.
2. Based on the microcode corresponding to the software interrupt instruction, the necessary
processes are performed, such as save of the dedicated registers. The branch processing is
then executed.
3. The RETI instruction is executed in user's interrupt processing routine to end interrupt
processing.
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Notes on software interrupts
If the program counter bank register (PCB) is set to "FF
duplicated with the table for INT #vct8 instructions. When creating software, make sure that the
CALLV instruction and INT #vct8 instruction have no address duplication.
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Figure 3.5-1 Software interrupt operation
PS,PC
(2) Microcode
RAM
PS I
(1)
IR
Queue
", the CALLV instruction vector area is
H
S
Fetch