External Interrupt (IRQ)
Functional Description
FROM RESET
YES
I BIT SET?
NO
YES
INTERRUPT?
NO
STACK CPU REGISTERS
SET I BIT
LOAD PC WITH INTERRUPT VECTOR
FETCH NEXT
INSTRUCTION
YES
SWI
INSTRUCTION?
NO
YES
RTI
INSTRUCTION?
UNSTACK CPU REGISTERS
EXECUTE INSTRUCTION
NO
Figure 8-3. IRQ Interrupt Flowchart
MC68HC908MR32 • MC68HC908MR16 — Rev. 6.0
MOTOROLA
Data Sheet
103
External Interrupt (IRQ)