ARM Instruction Set: Multiplication Instructions Assembler input: MUL ,, MLA ,,, Assembler output: High byte as standard Sixth nybble contains multiply subinstruction code and S flag Bits 21-23 (3-bit cardinal) are multiply subinstruction code Bit 20 is S flag Fifth nybble is destination register Fourth nybble is 0 in MUL, and augend register in MLA Third nybble is second factor Bit 7 is 1 (indicating multiply instruction, NOT AL instruction) Bits 5-6 are 0 Bit 4 is 1 (indicating that low nybble is a register) Low nybble is first factor The following are valid subinstruction codes: Value Base instruction mnemonic 0 MUL 1 MLA