Computer Architecture MIPS Instruction Set and Registers Lecture

Computer Architecture MIPS Instruction Set and Registers Lecture 13 Digital Design and Computer Architecture Harris & Harris Morgan Kaufmann / Elsevier, 2007 1

Levels of Abstraction 2

Computer Architecture • Instructions – Way to command a computer • Instruction Set – Group of instructions a computer understands • Operation – What to do • Operands – What to use 3

Instructions What do we want to command our computer to do? 4

Design Principle 1 Simplicity favors regularity 5

Design Principle 2 Make the common case fast 6

Operands Where does the computer get the operands? 7

Operands: Registers 8

Design Principle 3 Smaller is Faster 9

The Register Set Name Reg Usage $0 0 Const 0 $v 0 -$v 1 2 -3 Results & Expr. Eval. $a 0 -$a 3 4 -7 Procedure arguments $t 0 -$t 7 8 -15 Temporaries $s 0 -$s 7 16 -23 Saved variables $t 8 -$t 9 24 -25 More Temporaries $gp 28 Global Pointer $sp 29 Stack Pointer $fp 30 Frame Pointer $ra 31 Return address 10

Operands: Memory 11

Operands: Memory 12

Design Principle 4 Good design demands good compromises 13

Operands: Immediates 14

Machine Language • Binary representation of instructions – R-Type – I-Type – J-Type 15

Machine Language: R-Type 16

Machine Language: R-Type 17

Machine Language: I-Type 18

Machine Language: I-Type 19

Machine Language: J-Type 20

The Stored Program 21

Next Time Programming – Branches – Procedure calls – Addressing modes 22