Coding Instructions

Question	Answer
Coding Instructions	Paper 1
The '+' or '-' in an equation is called an (a)_______ and it performs on two (b)_______. In the same way, computers use these in assembly and machine code.	(a) operator (b) operands
The operator defines what process will be happening: What are they?	(a) 00000: SUB (b) 00001: ADD (c) 00010: MOV (d) 00011: DEC (e) 00100: INC (f) 00101: MOV
The registers are defined by binary numbers too: What are they?	(a) 000: A (b) 001: B (c) 010: C (d) 011: D
But what does each process mean? Can you give an example?	00000 XXX YYYYYYYY: SUBtract value in YYYYYYYY from register XXX 00000 010 00101001, SUBtract the value 00101001 [41] from register C: SUB C, 41
00001 XXX YYYYYYYY: ADD value in YYYYYYYY to register XXX 00001 001 00001111, ADD the value 00001111 [15] to register B: ADD B, 15	00010 XXX YYYYYYYY: MOVe value YYYYYYYY into register XXX 00010 011 10000000, MOVe value 10000000 [128] into register D: MOV D, 128
00011 XXX: DECrement [subtract 1 from the] value in register XXX 00011 011, DECrement 1 from register D: DEC D	00100 XXX: INCrement [add 1 to the] value in register XXX 00100 010, INCrement 1 to register C: INC C
000101 XXX YYYYYYYY: MOVe value in memory address YYYYYYYY into register XXX 00101 000 10000000, MOVe value in memory address 00001000 [8] to register A: MOV A, [8]	Just be able to identify the command against the 5-digit binary code!

Resource summary

	Created by Megan Aldington about 6 years ago