Consider a computer in which each instruction occupies one 16-bit word of memory. Assume that the program counter is set to location 333. The processor will next fetch the instruction at location 300. On succeeding instruction cycles, it will fetch instructions from locations 334, 335, 336, and so on. The program

fragment shown adds the contents of the memory word at address 3131, to the contents of the memory word at Addresses 4321 and 6543 store the result in the latter location.

The instruction contains bits that specify the action the processor is to take. The processor interprets the instruction and performs the required action as Add 2+11 whose result will become 13.