MC68HC908EY16 Datasheet, PDF (162/278 Pages) Motorola, Inc – Microcontrollers

System Integration Module (SIM)
FROM RESET
YES
IIBBIITTSSEETT??
NO
IRQ
YES
INTERRUPT
?
NO
ICG CLK MON ^YES
INTERRUPT
?
NO
OTHER
YES
INTERRUPTS
?
NO
STACK CPU REGISTERS
SET I BIT
LOAD PC WITH INTERRUPT VECTOR
FETCH NEXT
INSTRUCTION
SWI
INSTRUCTION
YES
?
NO
RTI
INSTRUCTION
YES
?
NO
UNSTACK CPU REGISTERS
EXECUTE INSTRUCTION
Figure 14-9. Interrupt Processing
14.5.1.1 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.
MC68HC908EY16 • MC68HC908EY8 Data Sheet, Rev. 10
162
Freescale Semiconductor