There are four T states during op-code fetch in the 8085. T1 is the ALE state, where the address is emitted and the RD- line goes true; TWAIT is zero or more wait states based on READY; T2 is the middle of the fetch, and the internal strobing of the op-code; T3 is the completion of the fetch and stabilization of the bus signals; and T4 is the internal processing cycle.
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.
The STA instruction in the 8085 has 13 T states, 4 for opcode fetch, 3 for low half immediate address fetch, 3 for high half immediate address fetch, and 3 for data write.
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.
The 8085 instruction MOV M,A requires two machine cycles and 7 T states. Cycle one is 3 T states for opcode fetch, plus 1 T state for opcode decode. Cycle two is 3 T state for operand store. These numbers do not include WAIT states. WAIT states are interposed between T2 and T3 of any memory access cycle, and the total number of WAIT states depends on the READY line.
Each instruction requires specific time for the execution of instruction and this time is called instruction cycle. Each instruction cycle consists 1 to 5 machine cycle -- opcode fetch, memory read, memory write, IO read, IO write and each machine cycle consist 3 to 6 T - states. Time required to execute 1 T-state = 1/ operating frequency of 8085 Microprocessor for example operating frequency = 2MHz then time required to execute 1 T-state = 0.5 uSec example: Calculate time required to execute instruction MOV C, A sol: This instruction has one machine cycle i.e. opcode fetch (In any instruction 1st cycle is always opcode fetch and opcode fetch consists 4 to 6 T state depend on the operation of particular instruction) so to execute MOV C, A required 4T states so time required to execute this instruction is 4*0.5usec = 2usec any other queries pls contect: nileshbahadure2000@yahoo.co.in example:Calculate the time required to execute LXI H,2000H sol:Here we have to draw opcode fetch and two memory reads as two bytes 00H and 20H have to be read from memory. i.e, opcode fetch+Memory reads *2(bytes address) =4+3+3 so to execute LXI H,2000H,the required T-states is 10T and time is 10*0.5usec=5usec
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
Three for opcode fetch, one for decode, two to process the manipulation of the stack pointer.
three
opcode: 3decode: 1address l fetch: 3address h fetch: 3If jump is not taken, address h fetch is skipped.
3 T states for instruction fetch, 1 T state for decode, 1 T state for register E decrement, 1 T state for possible register D decrement.
A T state is one cycle of the system clock.
different microprocessors take different number of states. without knowing processor its not possible to comment.