The process of transferring instruction codes from memory location to instruction queue register is called opcode fetch.
The microprocessor uses an opcode fetch cycle for every instruction because it has to know the opcode in order to execute it, and that is located in memory.
3 for opcode fetch, 1 for opcode decode, 3 for operand fetch, and 3 for opcode store, for a total of 10, not including wait states.
IP is incremented after fetch of instruction opcode. Specifically, IP is incremented by the number of opcode bytes.
the opcode is fetched from the memory and decoded
Three for opcode fetch, one for decode, two to process the manipulation of the stack pointer.
opcode: 3decode: 1address l fetch: 3address h fetch: 3If jump is not taken, address h fetch is skipped.
three
The OUT instruction on the 8085 uses 10 T cycles, 3 for opcode fetch, 1 for opcode decode, 3 for port address fetch, and 3 for port data store. Any wait states encountered are above and beyond that.
As far as the bus interface is concerned, there is no real difference between data and instructions. Except for the S0 pin, an opcode fetch will look the same as a memory read. There is one extra clock cycle following an opcode fetch, which is used by the CPU to decode and process the opcode, but the bus does not care because there is no sequence initiation with ALE.
It is a 3 byte instruction, with one byte for opcode and the other two for the 16bit address. It takes four machine cycles (one to fetch opcode, one to fetch lower order address, one to fetch higher order address and another one to fetch the data from the memory)... i.e. it takes 13 time states to perform the LDA instruction
It depends on the type of architecture and controller u use. It can be found in the instruction set documentation. It requires 18 cycles on the Intel 8085.How_many_machine_cycles_require_for_call_instruction_in_8085
The STA 4200H instruction in the 8085 requires 4 machine cycles and 13 T states to complete its fetch, processing, and execution. Cycle One: Opcode fetch, 3 T states plus one opcode process state. Cycle Two: Opcode address byte 00H fetch, 3 T states Cycle Three: Opcode address byte 42H fetch, 3 T states Cycle Four: Accumulator store, 3 T states. Each cycle will have additional T-Ready states as needed by the READY pin. 13 T states is the minimum. The LDA instruction will also require 13 T states, with the last cycle being a read cycle instead of a write cycle.