MC68HC05P9ACDW FREESCALE [Freescale Semiconductor, Inc], MC68HC05P9ACDW Datasheet - Page 56

• Manufacturer Part Number: MC68HC05P9ACDW
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Resets and Interrupts
Timer Overflow
Interrupt
Interrupt
Processing
56
A timer overflow interrupt request occurs if the timer overflow flag, TOF,
becomes set while the timer overflow interrupt enable bit, TOIE, is also
set. TOF is in the timer status register, and TOIE is in the timer control
register.
The CPU takes the following actions to begin servicing an interrupt:
The return from interrupt (RTI) instruction causes the CPU to recover the
CPU registers from the stack as shown in
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Stores the CPU registers on the stack in the order shown in
Figure 22
Sets the I bit in the condition code register to prevent further
interrupts
Loads the program counter with the contents of the appropriate
interrupt vector locations:
– $1FFC and $1FFD (software interrupt vector)
– $1FFA and $1FFB (external interrupt vector)
– $1FF8 and $1FF9 (timer interrupt vector)
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Resets and Interrupts
Figure
22.
12-mc68hc05p9a
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