中断从触发到响应

LiMeng

The interrupt execution response for all the enabled AVR interrupts is four clock cycles
minimum. After four clock cycles, the program vector address for the actual interrupt
handling routine is executed. During this 4-clock cycle period, the Program Counter is
pushed onto the Stack. The vector is normally a jump to the interrupt routine, and this
jump takes three clock cycles. If an interrupt occurs during execution of a multi-cycle
instruction, this instruction is completed before the interrupt is served. If an interrupt
occurs when the MCU is in Sleep mode, the interrupt execution response time is
increased by four clock cycles. This increase comes in addition to the start-up time from
the selected sleep mode.
A return from an interrupt handling routine takes four clock cycles. During these 4-clock
cycles, the Program Counter (two bytes) is popped back from the Stack, the Stack
Pointer is incremented by two, and the I-bit in SREG is set.

这是AVR数据手册上对中断的详细描述，有兴趣的可以翻译一下