all the interrupts may be assigned different priorities, so that whenever an interrupt

occurs while an interrupt handler is running, their priorities will be compared first, and the

further action will be determined according to the result

The aggregate data transfer demand approaches the capacity of the bus

Time it takes to perform a read or write operation, that is$,$ the time from the instant that

an address is presented to the memory to the instant that data have been stored or made

available for use.

Mechanism to control the access to a bus. Can be centralized ore distributed.

If an interrupt occurs during this time, it generally remains pending and will be checked

later.

disabling interrupt request while an interrupt is being processed, all interrupts will be

processed sequentially.

Number of bits or lines in the bus that identify the size.

DIV by zero, I$/$O$,$ Signal, Program request.