What happens when the INTR signal goes high in the 8085

Explain briefly what happens when the INTR signal goes high in the 8085



The INTR is a maskable interrupt for the 8085. It has the lowest priority and is also non vectored. When this INTR signal goes into the high state the following things occur / take place:

- For every instruction that is executed the 8085 checks the status of this interrupt./

- Till an instruction is completed the signal of INTR will remain high. Once an instruction is completed the processor sends an acknowledgement signal INTA.

- As soon as the INTA signal goes low a new opcode is placed on the data bus for transfer.

- Once the new instruction is received the processor saves the address of new instruction into the STACK and an interrupt service subroutine begins.
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