Lecture 10a: Instruction Set Architecture

Data types

MIPS supports 2's complement integers , unsigned integers , floating points

 

Operate Instruction

MIPS 

R-type instructions are binary operations

I-type instructions = immediate + R-type instruction

F type operation = floating-point operations.

 

the bits before immediate is to identify whether next bits are immediate or register.

In MIPS by seeing Opcode we can tell whether it is immediate or not

 

simple because we don't have to make decoder for more instructions and ALU.

 

 

Data movement instructions

PC realtive adderssing mode

 

Indirect Addressing Mode

we treat PCoffset9 as address and map it with real address. 

now the address of the operand can be anywherer in the memory

 

Base + Offset Addressing Mode

again the address of the operand can be anywherer in the memory , because each 8 registers have 16 bits and total memory address is 16bits.

 

Immediate Addressin mode

 

Branches

beq $s0 , $s1 , offset == just comparing registers whether they are equal or not.