That would depend on the computer architecture.
RST 2 is one example of a one byte call instruction. It points to 0010H.
A two-byte instruction gives the specific function instruction in two bytes, or two words. The first specifies the opcode, which tells the microprocessor what operation will occur. The second specifies the operand, or the data that the operation is done on.
There are 74 instructions in the 8085 microprocessor.
The RST instruction is a 1 byte opcode with a 3 bit imbedded operand. There are 8 different RST instructions. Each pushes the PC on the stack, and loads the PC with the operand's value times 8. (0H, 8H, 10H, 18H, etc.)Pushing the PC on the stack and loading a new value into the PC is exactly what a CALL instruction does, so the RST instruction is a 1 byte CALL instruction. The difference between RST and CALL is that CALL is a 3 byte instruction which can go anywhere in memory in one instruction.
32 byte
In 8086 the instruction queue is 6 byte long. This is because even the longest 8086 instruction is 6 byte long. Thus it is possible to prefetch even the longest instruction in the instruction set.
In a three-byte instruction, the second byte typically indicates additional information related to the operation specified by the first byte. This can include operand types, addressing modes, or specific registers being used. The exact meaning of the second byte can vary depending on the instruction set architecture (ISA) being utilized. Therefore, understanding the context of the ISA is crucial for interpreting the second byte correctly.
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.
32 byte
1byte instruction = MOV A,B 2byte instruction = MVI A,01H 3byte instruction = STA 2030H
The 8085 instruction set is classified into the following three groups according to word size: 1. One-word or 1-byte instructions 2. Two-word or 2-byte instructions 3. Three-word or 3-byte instructions
Suppose we give a 8-bit instruction ADD B to the microprocessor then this instruction is not at all understood by microprocessor as it only accepts binary inputs so first of all it stores the instruction in the INSTRUCTION REGISTOR then it decodes this instruction ADD B to its suitable binary code 80H in the INSTRUCTION DECODER.. after converting to 80H then the microprocessor understands that .. yes i have to add the content of the resistor B with that of A(accumulator) and store the result in the accumulator A this is a small example how microprocessor operates facing the instructions