How To Print Out Values From A Register In Mars Mips

MIPS assembly language but refers to the associates language of the MIPS processor. The term MIPS is an acronym for Microprocessor without Interlocked Pipeline Stages. It is a reduced-teaching set compages developed by an arrangement chosen MIPS Technologies.

The MIPS assembly language is a very useful language to learn because many embedded systems run on the MIPS processor. Knowing how to code in this language brings a deeper understanding of how these systems operate on a lower level.

Earlier you starting time coding in the MIPS assembly language

Before you start churning out MIPS associates language code, you lot need to first obtain a very good Integrated Evolution Environment. That tin help to compile and execute your MIPS assembly language lawmaking. The software that I would recommend this purpose is the MARS (MIPS Assembler and Runtime Simulator). Y'all tin notice it easily on Google, and download it.

Introduction to the MIPS architecture

Data Types

All the instructions in MIPS are 32 bits.
A byte in the MIPS compages represents 8 bits; a halfword represents 2 bytes (16 bits) and a discussion represents 4 bytes (32 bits).
Each character used in the MIPS compages requires one byte of storage. Each integer used requires 4 bytes of storage.

Literals
In the MIPS architecture, literals correspond all numbers (east.g. v), characters enclosed in unmarried quotes (due east.thou. 'g') and strings enclosed in double quotes (e.yard. "Deadpool").

Registers
MIPS architecture uses 32 general-purpose registers. Each register in this compages is preceded by '$' in the assembly language educational activity. Y'all can address these registers in one of two ways. Either use the register'south number (that is, from $0 to $31), or the annals's name (for example, $t1).

General structure of a program created using the MIPS assembly language

A typical program created using the MIPS associates language has two chief parts. They are the data declaration department of the plan and the code section of the program.

Information announcement section of a MIPS associates linguistic communication plan

The data declaration department of the program is the office of the plan identified with the assembler directive .data. This is the part of the program in which all the variables to exist used in the plan are created and divers. It is also the role of the program where storage is allocated in the chief memory (RAM).

The MIPS assembly language plan declares variables equally follows:

          proper name:          	.storage_type          	value(s)

The "proper noun" refers to the proper name of the variable being created. The "storage_type" refers to the type of data that the variable is meant to store. The "value(south)" refers to the information to be stored in the variable being created. The post-obit MIPS assembly language syntax creates a single integer variable with the initial value of 5:

          .information     var1:   	 .word   	 5

Code section of the MIPS associates language program

The lawmaking section of the program is the function of the program in which the instructions to be executed by the program are written. It is placed in the section of the program identified with the assembler directive .text. The starting point for the lawmaking department of the program is marked with the characterization "main" and the catastrophe point for the code section of the program is marked with an exit arrangement call. This department of a MIPS assembly language programme typically involves the manipulation of registers and the performance of arithmetic operations.

Manipulation of registers

In the manipulation of registers, the MIPS assembly linguistic communication utilizes the concepts of load, and indirect or indexed addressing.

In the concept of load addressing, the Random-Admission Retentiveness address of a variable in the MIPS assembly language program is copied and stored in a temporary annals. For instance, to copy the address of a variable called "var1" into the temporary annals $t0, the following MIPS associates linguistic communication syntax is required:

          la $t0, var1

In the concept of indirect addressing, the value stored in a item Random-Admission Memory address is copied into a temporary annals. For case, use the following MIPS assembly linguistic communication syntax to copy an integer value stored in the Random-Access Retentivity address of register $t0 into register $t2

          lw $t2, ($t0)

In the concept of indexed addressing, the Random-Admission Memory address of a register can be starting time by a specified value to obtain a value stored in some other Random-Admission Memory accost. For instance, to obtain the value stored in a Random-Access Memory address which is four addresses abroad from the Random-Access Memory address of the register $t0, and store that value in register $t2, the post-obit MIPS assembly language syntax is required:
lw $t2, four($t0)

Performance of arithmetic operations

In the MIPS assembly linguistic communication, most arithmetic operations utilize iii operands, and all these operands are registers. The size of each operand is a word, and the general format for performing arithmetic operations in the MIPS associates language is shown as follows:

          arithmetic_operation storage_register, first_operand, second_operand

Where "arithmetic_operation" refers to the arithmetics performance that is existence performed, "storage_register" refers to the register that is used to store the result of the arithmetic computation; "first_operand" refers to the register that contains the starting time operand of the arithmetic operation, and "second_operand" refers to the register that contains the 2d operand of the arithmetic operation.

The near common arithmetics operations implemented in the MIPS assembly linguistic communication are improver, subtraction, multiplication and division. The following table represents the diverse arithmetic operations that have been listed and how they are represented in the MIPS assembly language:

Creating a uncomplicated MIPS associates language plan

In this post, we create a simple plan that tin can obtain 2 different numbers from a user and perform the arithmetics operations of improver, subtraction and multiplication on those two numbers.

The get-go thing to do when creating this program is to define the variables that are to exist used to store the strings used in the program.

#This is a elementary programme to accept two numbers from the user and perform
#basic arithmetic functions such as addition, subtraction and multiplication with them

#Program menstruation:
#1. Print statements to ask the user to enter the ii dissimilar numbers
#2. Store the 2 numbers in dissimilar registers and print the 'card' of arithmetic instructions to the user
#3. Based on the option made by the user, create branch structures to perform the commands and print the issue
#4. Go out the program

          .information         prompt1:    .asciiz   	 "Enter the get-go number: "     prompt2:    .asciiz   	 "Enter the second number: "     bill of fare:   	 .asciiz   	 "Enter the number associated with the functioning you desire performed: 1 => add, ii => subtract or 3 => multiply: "     resultText:    .asciiz   	 "Your concluding event is: "

The second thing to do is to pre-load the integer values representing the various instructions to exist performed by the programme into their corresponding registers for storage.

          .text .globl main primary:     #The post-obit block of code is to pre-load the integer values representing the various instructions into registers for storage     li $t3, 1    #This is to load the immediate value of i into the temporary register $t3     li $t4, 2    #This is to load the immediate value of 2 into the temporary register $t4     li $t5, 3    #This is to load the immediate value of 3 into the temporary annals $t5

So, impress out the instructions that crave the user to input the two numbers that they would like to perform the arithmetic operations on.

          #asking the user to provide the get-go number     li $v0, 4     #command for printing a string     la $a0, prompt1 #loading the string to print into the argument to enable printing     syscall   	 #executing the command                #the next block of code is for reading the get-go number provided by the user     li $v0, 5    #command for reading an integer     syscall   	 #executing the command for reading an integer     motion $t0, $v0     #moving the number read from the user input into the temporary register $t0          #asking the user to provide the second number     li $v0, 4    #command for printing a string     la $a0, prompt2    #loading the string into the argument to enable printing     syscall   	 #executing the command               #reading the second number to exist provided to the user     li $v0, 5    #control to read the number  provided by the user     syscall   	 #executing the command for reading an integer     move $t1, $v0    #moving the number read from the user input into the temporary register $t1

The adjacent step is to print out the commands the user can perform on the two numbers that have been provided. This is to enable the user to select a course of activeness.

#the next cake of code is to print all of the commands that the user tin accept with regards to the #two numbers that he or she has provided

          li $v0, 4    #command for printing a string     la $a0, menu    #loading the cord into the argument to enable printing     syscall   	 #executing the control            #the adjacent cake of lawmaking is to read the number provided past the user     li $v0, v    #control for reading an integer     syscall   	 #executing the command     move $t2, $v0    #this command is to move the integer provided into the temporary register $t2

At this point, you demand to create control structures that determine which instructions are to be executed based on the command issued by the user.

The following lines of code determine what should take identify depending on the integer value # that was provided by the user

          beq $t2,$t3,addProcess    #Co-operative to 'addProcess' if $t2 = $t3     beq $t2,$t4,subtractProcess #Branch to 'subtractProcess' if $t2 = $t4     beq $t2,$t5,multiplyProcess #Branch to 'multiplyProcess' if $t2 = $t5

The adjacent lawmaking instructs adding the 2 numbers provided.

          addProcess:     add $t6,$t0,$t1    #this adds the values stored in $t0 and $t1 and assigns them to the     temporary register $t6          #The following line of code is to print the results of the ciphering above     li $v0,iv    #this is the command for press a string     la $a0,resultText    #this loads the string to print into the argument $a0 for printing     syscall   	 #executes the command          #the post-obit line of lawmaking prints out the outcome of the add-on computation     li $v0,i     la $a0, ($t6)     syscall          li $v0,10 #This is to stop the programme

This is an example of code for instructions to subtract the two numbers provided.

          subtractProcess:     sub $t6,$t0,$t1 #this adds the values stored in $t0 and $t1 and assigns them to the temporary annals $t6     li $v0,4    #this is the control for printing a string     la $a0,resultText    #this loads the string to print into the argument $a0 for printing     syscall   	 #executes the command          #the following line of lawmaking prints out the result of the addition computation     li $v0,ane     la $a0, ($t6)     syscall          li $v0,10 #This is to terminate the program

This code is for instructions to multiply the two numbers provided.

          multiplyProcess:     mul $t6,$t0,$t1 #this adds the values stored in $t0 and $t1 and assigns them to the temporary register $t6     li $v0,4    #this is the control for press a cord     la $a0,resultText    #this loads the string to print into the statement $a0 for printing     syscall   	 #executes the command          #the post-obit line of lawmaking prints out the result of the addition computation     li $v0,one     la $a0, ($t6)     syscall          li $v0,x #This is to terminate the plan

When you are done implementing the code shown above, simply compile your program and run information technology. Congratulations! You have implemented your get-go MIPS assembly language program. 😊

Additional references to learn more about MIPS associates language syntax:
https://chortle.ccsu.edu/AssemblyTutorial/alphabetize.html

Conclusion

:
I hope that in this tutorial you accept received all the basic skills you need to aid you lot to create a very uncomplicated MIPS assembly linguistic communication programme.