CHAPTER 4: MIPS (Million Instructions Per Second)

Well hello! *do i need to introduce myself??

       For this chapter, I will be the one who will explain to you what is MIPS. So, what you will learn here is:

      1. MIPS Architecture
      2. Register       3. Comment (#)      4. Assembly Instruction     5. Memory Operand

4.1 MIPS Architecture

          

    - a unit of computing speed equivalent to a million instructions per second.

    - an early RISC processor. RISC processors typically support fewer and much simpler instructions.

4.2 Register

    - limited number of special location built directly into the hardware
    - needd to perform the operation (cannot perform without it)
    - very fast since registers are directly in hardware
    - only 32 registers in MIPS

• why? smaller the register, faster the performance

    - 1 register is 32 bits wide (32 bits = a word)

    - register preceded by $ in assembly language instruction

    - two formats for addressing:

• using register number e.g. $0 through $31
• using equivalent names e.g. $t1, $sp

    - special registers Lo and Hi used to store result of multiplication and division

• not directly addressable: contents accessed with special instruction mfhi ("move from Hi") and mflo ("move from Lo")   

    - stack grows from high memory to low memory

4.3 Comment

      In programming language, we create comment by putting '//' at the front. Hence,in assembly language (coding in MIPS), we use put '#' (hashtag) before the words.

#comment

    - hash (#) is used for MIPS comments

• anything from hash mark to the end of line is a comment
• will be ignored in the coding

4.4 Assembly Instructions

    - in assembly language, instruction is a statement

    - each instruction is executed exactly one with a simple command

    

     Syntax of instructions:

     The arrangement of coding ::       1(ON)  2(Ds),3(S1),4(S2)

     1(ON) ---> operation name (ADD, SUB, etc)

     2(S0)  ---> operand for getting result or we called it ('destination')

     3(S1)  ---> 1st operand for operation called ('source1')

     4(S2)  ---> 1st operand for operation called ('source2')

     example :   add  $s0,$s1,$s2 

    

     - Syntax is rigid

• 1 operator (add,sub, etc), 3 operands >> to keep hardware simple and fast

     :: Addition in assembly

         Example:               add  $s0,$s1,$s2  (in MIPS)

         is equal to:            a = b + c (in C)

   

     :: Subtraction in assembly

         Example:               sub  $s3,$s4,$s5  (in MIPS)

         is equal to:            d = e - f (in C)

4.5 Memory Operand

    

     - Main memory used for omposite data

     - To apply arithmetic operations

• load values from memory into registers
• store result from register to emory

     - memory is byte addressed

• each address identifies an 8-bit byte

     - words are aligned in memory

• address must be a multiple of 4

That's all from me. Hope you enjoys reading mine! Ppyong~

Reference

Reference