Operatori Verilog

Verilog Operators Operate On Several Data Types To Produce An Output

I Not All Verilog Operators Are Synthesible (Can Produce Gates)

I Some Operators Are Similar To Those In The C Language

I Remember, You Are Making Gates, Not An Algorithm (In Most Cases)

Verilog - Operators

Arithmetic Operators

I There Are Two Types Of Operators: Binary And Unary

I Binary Operators:

I Add(+), Subtract(-), Multiply(*), Divide(/), Power(**), Modulus(%)

//Suppose That: A = 4’b0011;

// B = 4’b0100;

// D = 6; E = 4; F = 2;

//Then,

A + B //Add A And B; Evaluates To 4’b0111

B - A //Subtract A From B; Evaluates To 4’b0001

A * B //Multiply A And B; Evaluates To 4’b1100

D / E //Divide D By E, Evaluates To 4’b0001. Truncates Fractional Part

E ** F //Raises E To The Power F, Evaluates To 4’b1111

//Power Operator Is Most Likely Not Be Synthesible

If Any Operand Bit Has A Value ”x”, The Result Of The Expression Is All ”x”.

If An Operand Is Not Fully Known The Result Cannot Be Either.

Verilog - Operators

Arithmetic Operators (Cont.)

Modulus Operator Yields The Remainder From Division Of Two Numbers

It Works Like The Modulus Operator In C

May Or May Not Be Synthesible

3 % 3; //Evaluates To 1

16 % 4; //Evaluates To 0

-7 % 2; //Evaluates To -1, Takes Sign Of First Operand

7 % -2; //Evaluates To -1, Takes Sign Of First Operand

Verilog - Operators

Arithmetic Operators (Cont.)

I Unary Operators

I Operators ”+” And ”-” Can Act As Unary Operators

I They Indicate The Sign Of An Operand

I.E., -4 // Negative Four

+5 // Positive Five

!!! Negative Numbers Are Represented As 2’s Compliment Numbers !!!

!!! Use Negative Numbers Only As Type Integer Or Real !!!

!!! Avoid The Use Of <Sss>’<Base><Number >In Expressions !!!

!!! These Are Converted To Unsigned 2’s Compliment Numbers !!!

!!! This Yields Unexpected Results In Simulation And Synthesis !!!