Hardware interrupts

       8085 has five hardware interrupt signals that can be used to interrupt program execution.these signals are
            (1)TRAP
            (2)RST 7.5
            (3)RST 6.5
            (4)RST 5.5
            (5)INTR/INTA
      

TRAP (PIN 6):

    Trap is highest priority, nonmaskable interrupt, when trap is received microprocessor starts the program execution from location (4.5*8) =0024H. this is why it is also called as vectored interrupt.

RST 7.5, 6.5, 5.5 (PIN 7,8,9):
     These are restart interrupts or vectored interrupt. these are maskable interrupt and has lower priority than TRAP, among these RST 7.5 has the highest priority and RST 5.5 having the lowest.

INTR (PIN 10):
    Interrupt request - this signal is used as a general purpose interrupt.it has lowest priority and is a maskable interrupt.

INTA (PIN 11):
     This is interrupt acknowledgement signal sent by the processor when INTR is recognized. This is active low signal.