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Tutorials



OPERATORS PART 1

Operators :



Concatenation
Arithmetic Operators
Relational Operators
Equality Operators
Logical Operators
Bit-wise Operators
Reduction Operators
Shift Operators
Increment and Decrement Operators
Conditional Operator


Concatenation :



{} concatenation right of assignment.
´{} concatenation left of assignment.




EXAMPLE :Concatenation
program main {
bit [4:0] a;
bit b,c,d;
b = 0;
c = 1;
d = 1;
a = {b,c,0,0,d};
`{b,c,d} = 3'b111;
printf(" a %b b %b c %b d %b ",a,b,c,d);
}

RESULTS

a 00001 b 1 c 1 d 1



Arithmetic :



# - unary arithmetic (negative)
# +, -, *, / binary arithmetic
# % modulus




EXAMPLE :Arithmetic
program main {
integer a,b;
b = 10;
a = 22;

printf(" -(nagetion) is %0d \n",-(a) );
printf(" a + b is %0d \n",a+b);
printf(" a - b is %0d \n",a-b);
printf(" a * b is %0d \n",a*b);
printf(" a / b is %0d \n",a/b);
printf(" a modulus b is %0d \n",a%b);

}


RESULTS

-(nagetion) is -22
a + b is 32
a - b is 12
a * b is 220
a / b is 2
a modules b is 2



Relational :



# > >= < <= relational



EXAMPLE :Relational
program main {
integer a,b;
b = 10;
a = 22;

printf(" a < b is %0d \n",a < b);
printf(" a > b is %0d \n",a >b);
printf(" a <= b is %0d \n",a <= b);
printf(" a >= b is %0d \n",a >= b);

}
RESULTS

a < b is 0
a > b is 1
a <= b is 0
a >= b is 1


Equality :



== logical equality
!= logical inequality
=== case equality
!== case inequality
=?= wildcard equality
!?= wildcard inequality



EXAMPLE :logical Equality
reg[3:0] a;
reg[7:0] x, y, z;
a = 4'b0101;
x = 8'b1000_0101;
y = 8'b0000_0101;
z = 8'b0xx0_0101;
if (x == a)
printf("x equals a is TRUE.\n");
if (y == a)
printf("y equals a is TRUE.\n");
if (z == a)
printf("z equals a is TRUE.\n");
RESULTS

y equals a is TRUE.

EXAMPLE : Case equality
program main {
reg a_1,a_0,a_x,a_z;
reg b_1,b_0,b_x,b_z;
a_1 = 'b1;a_0 = 'b0;a_x = 'bx;a_z = 'bz;
b_1 = 'b1;b_0 = 'b0;b_x = 'bx;b_z = 'bz;
printf("--------------------------\n");
printf (" == 0 1 x z \n");
printf("--------------------------\n");
printf (" 0 %b %b %b %b \n",a_0 == b_0,a_0 == b_1,a_0 == b_x,a_0 == b_z);
printf (" 1 %b %b %b %b \n",a_1 == b_0,a_1 == b_1,a_1 == b_x,a_1 == b_z);
printf (" x %b %b %b %b \n",a_x == b_0,a_x == b_1,a_x == b_x,a_x == b_z);
printf (" z %b %b %b %b \n",a_z == b_0,a_z == b_1,a_z == b_x,a_z == b_z);
printf("--------------------------\n");
printf("--------------------------\n");
printf (" === 0 1 x z \n");
printf("--------------------------\n");
printf (" 0 %b %b %b %b \n",a_0 === b_0,a_0 === b_1,a_0 === b_x,a_0 === b_z);
printf (" 1 %b %b %b %b \n",a_1 === b_0,a_1 === b_1,a_1 === b_x,a_1 === b_z);
printf (" x %b %b %b %b \n",a_x === b_0,a_x === b_1,a_x === b_x,a_x === b_z);
printf (" z %b %b %b %b \n",a_z === b_0,a_z === b_1,a_z === b_x,a_z === b_z);
printf("--------------------------\n");
printf("--------------------------\n");
printf (" =?= 0 1 x z \n");
printf("--------------------------\n");
printf (" 0 %b %b %b %b \n",a_0 =?= b_0,a_0 =?= b_1,a_0 =?= b_x,a_0 =?= b_z);
printf (" 1 %b %b %b %b \n",a_1 =?= b_0,a_1 =?= b_1,a_1 =?= b_x,a_1 =?= b_z);
printf (" x %b %b %b %b \n",a_x =?= b_0,a_x =?= b_1,a_x =?= b_x,a_x =?= b_z);
printf (" z %b %b %b %b \n",a_z =?= b_0,a_z =?= b_1,a_z =?= b_x,a_z =?= b_z);
printf("--------------------------\n");
printf("--------------------------\n");
printf (" != 0 1 x z \n");
printf("--------------------------\n");
printf (" 0 %b %b %b %b \n",a_0 != b_0,a_0 != b_1,a_0 != b_x,a_0 != b_z);
printf (" 1 %b %b %b %b \n",a_1 != b_0,a_1 != b_1,a_1 != b_x,a_1 != b_z);
printf (" x %b %b %b %b \n",a_x != b_0,a_x != b_1,a_x != b_x,a_x != b_z);
printf (" z %b %b %b %b \n",a_z != b_0,a_z != b_1,a_z != b_x,a_z != b_z);
printf("--------------------------\n");
printf("--------------------------\n");
printf (" !== 0 1 x z \n");
printf("--------------------------\n");
printf (" 0 %b %b %b %b \n",a_0 !== b_0,a_0 !== b_1,a_0 !== b_x,a_0 !== b_z);
printf (" 1 %b %b %b %b \n",a_1 !== b_0,a_1 !== b_1,a_1 !== b_x,a_1 !== b_z);
printf (" x %b %b %b %b \n",a_x !== b_0,a_x !== b_1,a_x !== b_x,a_x !== b_z);
printf (" z %b %b %b %b \n",a_z !== b_0,a_z !== b_1,a_z !== b_x,a_z !== b_z);
printf("--------------------------\n");
printf("--------------------------\n");
printf (" !?= 0 1 x z \n");
printf("--------------------------\n");
printf (" 0 %b %b %b %b \n",a_0 !?= b_0,a_0 !?= b_1,a_0 !?= b_x,a_0 !?= b_z);
printf (" 1 %b %b %b %b \n",a_1 !?= b_0,a_1 !?= b_1,a_1 !?= b_x,a_1 !?= b_z);
printf (" x %b %b %b %b \n",a_x !?= b_0,a_x !?= b_1,a_x !?= b_x,a_x !?= b_z);
printf (" z %b %b %b %b \n",a_z !?= b_0,a_z !?= b_1,a_z !?= b_x,a_z !?= b_z);
printf("--------------------------\n");
}

RESULTS

--------------------------
== 0 1 x z
--------------------------
0 1 0 x x
1 0 1 x x
x x x x x
z x x x x
--------------------------
--------------------------
=== 0 1 x z
--------------------------
0 1 0 0 0
1 0 1 0 0
x 0 0 1 0
z 0 0 0 1
--------------------------
--------------------------
=?= 0 1 x z
--------------------------
0 1 0 1 1
1 0 1 1 1
x 1 1 1 1
z 1 1 1 1
--------------------------
--------------------------
!= 0 1 x z
--------------------------
0 0 1 x x
1 1 0 x x
x x x x x
z x x x x
--------------------------
--------------------------
!== 0 1 x z
--------------------------
0 0 1 1 1
1 1 0 1 1
x 1 1 0 1
z 1 1 1 0
--------------------------
--------------------------
!?= 0 1 x z
--------------------------
0 0 1 0 0
1 1 0 0 0
x 0 0 0 0
z 0 0 0 0
--------------------------


Index
Introduction
Data Types
Linked List
Operators Part 1
Operators Part 2
Operators Part 3
Operator Precedence
Control Statements
Procedures And Methods
Interprocess
Fork Join
Shadow Variables
Fork Join Control
Wait Var
Event Sync
Event Trigger
Semaphore
Regions
Mailbox
Timeouts
Oop
Casting
Randomization
Randomization Methods
Constraint Block
Constraint Expression
Variable Ordaring
Aop
Predefined Methods
String Methods
Queue Methods
Dut Communication
Functional Coverage

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