250 THE x86 MICROPROCESSORS
received, the processor performs the ‘interrupt service routine’ (ISR) which is the process of
identifying the key that was pressed. is, in essence, is the philosophy of interrupts and it helps
utilize the processor with maximum effi ciency.
8.1 | Interrupts of 8086
Now that we have accepted that interrupts are a part of the normal working of a processor, let
us see the interrupt processing mechanism of 8086. 8086 has hardware interrupts, software
interrupts and error generated interrupts. For the three cases mentioned here, the interrupting
mechanism is diff erent, but the way the processor responds is similar. So let us fi rst have a look
at the way 8086 responds to any interrupt. e point to note is that, af ...