Incorrect. Fetching and decoding of any instruction takes a minimum of four clock cycles in the 8085.
T1 = ALE and address emission
T2 = Read initiation
T3 = Read completion
T4 = Opcode decode
T1, T2, and T3 are repeated for each additional byte of the instruction. In all cases, Twait, if indicated by not READY, is inserted between T2 and T3.
Depending on the particular microprocessor, a machine cycle is the fetch or store of one (typically, one byte) native word. In the 8085, this is a byte fetch or store, plus the overhead in decoding and processing the instruction. In this case, the first machine cycle is four clock cycles, or T states, and subsequent machine cycles are three clock cycles, although certain instruction sequences, such as DAD, require two extra clock cycles.
There are three fetch cycles in a three byte instruction. The first one is four clock cycles long, while the other two are three clock cycles long. Depending on what the instruction does, there will then be more read/write cycles.
CALL, requiring 18 clock cycles.
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.
The CALL instruction uses 18 clock cycles. 3x3 fetch, 2x3 store, 1x1 decode, 2x1 decrement.
The key components of the CPI (Clocks Per Instruction) in computer architecture are the clock cycle time and the number of instructions executed. The CPI measures the efficiency of a processor by indicating how many clock cycles are needed to execute an instruction. A lower CPI indicates better performance, as it means fewer clock cycles are needed to complete an instruction.
It depends on the processor. They often have a different number of Cycles per Instruction. (http://en.wikipedia.org/wiki/Cycles_Per_Instruction)
In the context of the 8086 microprocessor, the prefetch queue is a 6-byte high-speed queue that stores the next instruction to be executed. This helps improve performance by fetching instructions in advance and storing them in the queue. When the CPU is ready to execute the next instruction, it can quickly access it from the prefetch queue without having to wait for the instruction to be fetched from memory.
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.
Bus cycle refers to the process of transferring data between the CPU and memory or peripherals, while instruction cycle refers to the series of steps that the CPU goes through to fetch, decode, and execute instructions. In other words, bus cycle involves the movement of data, while instruction cycle involves the actual execution of instructions.
1.7 * 10^9 = Clock Cycles
In order to determine the instructions per second in an 8085 microprocessor, you need to know how long each instruction takes to execute. Some are as short as 4 T cycles. Some are as long as 18 T cycles. This is dependent on how the program is written. Add up the T cycles for each instruction. Divide the clock frequency in hertz by the number of T cycles, and you get instructions per second. Note that clock frequency is one half of the crystal frequency. Note also that you must include Twait cycles in your calculation.