Explain Briefly What Happens When The Intr Signal Goes High In The 8085?
1 Answer
Answer :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.
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.