MC68HC908GT16_07 FREESCALE [Freescale Semiconductor, Inc], MC68HC908GT16_07 Datasheet - Page 187

• Manufacturer Part Number: MC68HC908GT16_07
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

15.5.1.1 Hardware Interrupts
A hardware interrupt does not stop the current instruction. Processing of a hardware interrupt begins after
completion of the current instruction. When the current instruction is complete, the SIM checks all pending
hardware interrupts. If interrupts are not masked (I bit clear in the condition code register) and if the
corresponding interrupt enable bit is set, the SIM proceeds with interrupt processing; otherwise, the next
instruction is fetched and executed.
If more than one interrupt is pending at the end of an instruction execution, the highest priority interrupt is
serviced first.
Freescale Semiconductor
Figure 15-11
MC68HC908GT16 • MC68HC908GT8 • MC68HC08GT16 Data Sheet, Rev. 5.0
AS MANY INTERRUPTS
demonstrates what happens when two interrupts are pending. If an interrupt
AS EXIST ON CHIP
YES
Figure 15-10. Interrupt Processing
INSTRUCTION?
INSTRUCTION?
INSTRUCTION
FROM RESET
INTERRUPT?
FETCH NEXT
INTERRUPT?
I BIT SET?
I BIT SET?
BREAK
SWI
IRQ
RTI
NO
NO
NO
NO
NO
YES
YES
YES
YES
LOAD PC WITH INTERRUPT VECTOR
UNSTACK CPU REGISTERS
EXECUTE INSTRUCTION
STACK CPU REGISTERS
SET I BIT
Exception Control
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