Question 11881 – UGC NET CS 2014 Dec – paper-3

Software interrupt is caused either by an exceptional condition in the processor itself, or a special instruction in the instruction set which causes an interrupt when it is executed.
It is used for switching from a CPU user mode to supervisor mode.
Software interrupts is internal interrupt triggered by some software instruction.
There are 8 software interrupts in 8085 microprocessor. They are – RST 0, RST 1, RST 2, RST 3, RST 4, RST 5, RST 6, RST 7.
External interrupt: External interrupts are the interrupts caused by the hardware module. pressing a key on the keyboard or moving the mouse triggers hardware interrupts that cause the processor to read the keystroke or mouse position.