What is the interval of time from the instant an interrupt is accepted, until the corresponding interrupt service routine begins to execute ?

Microcomputer Frequently Asked Questions (FAQs) NO.EB9901201

Answer: The interval of time from the acceptance of an interrupt to the start of execution of the corresponding interrupt service routine varies with product type and operating frequency.
In the 8-bit microcontroller TMP86FS49, if an interrupt is accepted while an instruction is being executed, the interrupt service routine begins to execute eight machine cycles after the completion of this instruction. A machine cycle is the minimum execution unit of an instruction. If the operating frequency is 16 MHz, the interrupt service routine begins to execute a minimum of 2 µs after the completion of the instruction. For details, see the datasheet of each product.