Question

How a microprocessor 8085 does executes an instruction?

Answer 1

Each instruction of the 8085 processor consists of one to five machine cycles, i.e., when the 8085 processor executes an instruction, it will execute some of the machine cycles in a specific order.

The processor takes a definite time to execute the machine cycles. The time taken by the processor to execute a machine cycle is expressed in T-states.

One T-state is equal to the time period of the internal clock signal of the processor.

The T-state starts at the falling edge of a clock.

In this time, the first, 3 T-states are used for fetching the opcode from memory and the remaining T-states are used for internal operations by the processor.