The NOP (No Operation) instruction takes time but does nothing to the data or the status of the microprocessor. When executed in a loop, it can take substantial time, from microseconds, to milliseconds, to seconds.
The NOP instruction is a no-operation instruction. It does nothing to the state of the machine, except to use some time. In the case of the 8085, it uses four clock cycles plus however many wait states are need to access the NOP instruction from memory.
halt,DI (disable intrupts ),EI (enable intrupts),NOP(do nothing)
At a crystal frequency of 6MHz, the 8085 microprocessor has a clock frequency of 3MHz, or a period of 333 nanoseconds. The NOP instruction requires four clock cycles, three to fetch and one to execute, so the NOP instruction with a crystal frequency of 6MHz would take 1.333 microseconds to fetch and execute. This does not include wait states, each of which would add 0.333 microseconds to the timing.
There is no exit instruction in the 8085. Do you mean return, as in from a function or interrupt? If so, the instruction is RET.
Not in the 8085.
There are 74 instructions in the 8085 microprocessor.
MUL is not an 8085 instruction.
The NOP instruction is short for no-operation. It is an executable instruction that does nothing to the processor, its registers, or its flags. It is useful in timing loops, or to provide room for patchabilty of a piece of code.
CALL, requiring 18 clock cycles.
There are 74 instructions in the 8085 microprocessor.
The MOV A,A instruction in the 8085 does nothing, not even change flags. It only consumes time, specifically four clock cycles plus applicable wait states.
There are no instructions in the 8085 that execute in only one clock pulse. The minimum number of clock cycles is four; three for instruction fetch and one for instruction decode/execute.