MIPS: machine model

Main memory

data: 32-bit address: range from 0x00000000 to 0xFFFFFFFF

upper half of range reserved (see fig. 3-22)

Processor

registers: store data to perform operations

faster than main memory

load-store architecture

access memory only through load, store instructions

load: register <--- data from memory

store: register ---> data to memory

amount of data in bytes (1, 2, 4, 8) depends on instruction

all other operations use only registers or immediate values

immediate: contained in instruction

CISC: may use register and memory to perform operation

32-bit registers

32 general-purpose registers

$r0-$r31

Design Principle #2: "Smaller is faster."

16 floating point registers

ALU: arithmetic-logic unit

performs operations on values in registers

control: determines how operations executed ("computer within computer")