RELATIVE ADDRESSING

Inside the debugger the instruction is shown as JMP 0119 and the location 0119 contains the original first instruction of the logic of our program. This jump is unconditional, it will always be taken. Now looking at the opcode we see F21600 where F2 is the opcode and 1600 is the operand to it. 1600 is 0016 in proper word order. 0119 is not given as a parameter rather 0016 is given.

This is position relative addressing in contrast to absolute addressing. It is not telling the exact address rather it is telling how much forward or backward to go from the current position of IP in the current code segment. So the instruction means to add 0016 to the IP register. At the time of execution of the first instruction at 0100 IP was pointing to the next instruction at 0103, so after adding 16 it became 0119, the desired target location. The mechanism is important to know, however all calculations in this mechanism are done by the assembler and by the processor. We just use a label with the JMP instruction and are ensured that the instruction at the target label will be the one to be executed.