Hello, in this blog we will see classes examples in Systemverilog. Here only examples are describe there is no explanation about example. In each example there is link for executing code in edaplayground.
// Reference : verification guide classes
// ex1 set() and get() in class
class packet;
int loop_count; // class property
task set(int x); // class method
$display("---- Inside set() ---");
loop_count=x;
endtask
function int get(); // class method
$display("--- Inside get() ---");
return loop_count;
endfunction
endclass
module ex1;
packet pkt1,pkt2;
initial begin
pkt1=new();
pkt2=new();
$display("----------------------------------------------");
$display("---- pkt1.set(100) -----");
pkt1.set(100);
$display("--- pkt1.get() = %0d ---",pkt1.get());
$display("---- pkt2.set(200) -----");
pkt2.set(200);
$display("--- pkt2.get() = %0d ---",pkt2.get());
$display("----------------------------------------------");
end
endmodule
/* output
# KERNEL: ----------------------------------------------
# KERNEL: ---- pkt1.set(100) -----
# KERNEL: ---- Inside set() ---
# KERNEL: --- Inside get() ---
# KERNEL: --- pkt1.get() = 100 ---
# KERNEL: ---- pkt2.set(200) -----
# KERNEL: ---- Inside set() ---
# KERNEL: --- Inside get() ---
# KERNEL: --- pkt2.get() = 200 ---
# KERNEL: ----------------------------------------------
Link : https://www.edaplayground.com/x/9fwF
*/
// this keyword example : example 2
class packet;
bit [7:0] addr;
bit [7:0] data;
bit rdn_wr;
function new(bit[7:0] addr,data,bit rdn_wr);
this.addr = addr;
this.data = data;
this.rdn_wr= rdn_wr;
endfunction
function void display();
$display("---------------------------------");
$display("\taddr = %0d",addr);
$display("\tdata = %0d",data);
$display("\trdn_wr = %0b",rdn_wr);
$display("---------------------------------\n");
endfunction
endclass
module ex2;
packet pkt1,pkt2;
initial begin
pkt1=new(10,20,1);
pkt2=new(30,40,0);
$display("----------- pkt1.display() -------");
pkt1.display();
$display("----------- pkt2.display() -------");
pkt2.display();
end
endmodule
/* output
# KERNEL: ----------- pkt1.display() -------
# KERNEL: ---------------------------------
# KERNEL: addr = 10
# KERNEL: data = 20
# KERNEL: rdn_wr = 1
# KERNEL: ---------------------------------
# KERNEL:
# KERNEL: ----------- pkt2.display() -------
# KERNEL: ---------------------------------
# KERNEL: addr = 30
# KERNEL: data = 40
# KERNEL: rdn_wr = 0
# KERNEL: ---------------------------------
Link : https://www.edaplayground.com/x/AkV2
*/
// class constructor : example 3
class packet;
bit [31:0] addr;
bit [31:0] data;
function new();
addr=100;
data=25;
endfunction
function display();
$display("----------------------------------");
$display("\t addr=%0d",addr);
$display("\t data=%0d",data);
$display("----------------------------------\n");
endfunction
endclass
module ex3;
packet pk1,pk2;
initial begin
pk1=new();
pk2=new();
$display("---------- pk1.display() ----------");
pk1.display();
$display("---------- pk2.display() ----------");
pk2.display();
end
endmodule
/* output
# KERNEL: ---------- pk1.display() ---------
# KERNEL: ----------------------------------
# KERNEL: addr=100
# KERNEL: data=25
# KERNEL: ----------------------------------
# KERNEL:
# KERNEL: ---------- pk2.display() ---------
# KERNEL: ----------------------------------
# KERNEL: addr=100
# KERNEL: data=25
# KERNEL: ----------------------------------
Link : https://www.edaplayground.com/x/TVcz
*/
// stsatic variable : example 4
class packet;
static int count_objects;
function new();
count_objects++;
endfunction
function display();
$display("No of Objects Created = %0d",count_objects);
endfunction
endclass
module ex4;
initial begin
packet pkt[50];
$display("---------------------------------");
foreach(pkt[i])
begin
pkt[i]=new();
end
pkt[20].display();
$display("---------------------------------");
end
endmodule
/*
# KERNEL: ---------------------------------
# KERNEL: No of Objects Created = 50
# KERNEL: ---------------------------------
Link : https://www.edaplayground.com/x/ZhaR
*/
class packet;
static int unsigned count_objects;
int unsigned count_id;
function new();
count_id=count_objects;
count_objects++;
endfunction
static function display();
$display("No of Obj Created = %0d",count_objects);
endfunction
endclass
module ex4;
initial begin
packet pkt[50];
foreach(pkt[i])
begin
$display("Obj pkt[%0d] created",i);
pkt[i]=new();
end
$display("-------- pkt[0-to-49].display() ----------- ");
pkt[20].display();
$display("-------- pkt[20].count_id = %0d ----------- ",pkt[20].count_id);
$display("------------------------------------------- ");
end
endmodule
/* output
# KERNEL: Obj pkt[0] created
# KERNEL: Obj pkt[1] created
# KERNEL: Obj pkt[2] created
# KERNEL: Obj pkt[3] created
# KERNEL: Obj pkt[4] created
# KERNEL: Obj pkt[5] created
# KERNEL: Obj pkt[6] created
# KERNEL: Obj pkt[7] created
# KERNEL: Obj pkt[8] created
# KERNEL: Obj pkt[9] created
# KERNEL: Obj pkt[10] created
# KERNEL: Obj pkt[11] created
# KERNEL: Obj pkt[12] created
# KERNEL: Obj pkt[13] created
# KERNEL: Obj pkt[14] created
# KERNEL: Obj pkt[15] created
# KERNEL: Obj pkt[16] created
# KERNEL: Obj pkt[17] created
# KERNEL: Obj pkt[18] created
# KERNEL: Obj pkt[19] created
# KERNEL: Obj pkt[20] created
# KERNEL: Obj pkt[21] created
# KERNEL: Obj pkt[22] created
# KERNEL: Obj pkt[23] created
# KERNEL: Obj pkt[24] created
# KERNEL: Obj pkt[25] created
# KERNEL: Obj pkt[26] created
# KERNEL: Obj pkt[27] created
# KERNEL: Obj pkt[28] created
# KERNEL: Obj pkt[29] created
# KERNEL: Obj pkt[30] created
# KERNEL: Obj pkt[31] created
# KERNEL: Obj pkt[32] created
# KERNEL: Obj pkt[33] created
# KERNEL: Obj pkt[34] created
# KERNEL: Obj pkt[35] created
# KERNEL: Obj pkt[36] created
# KERNEL: Obj pkt[37] created
# KERNEL: Obj pkt[38] created
# KERNEL: Obj pkt[39] created
# KERNEL: Obj pkt[40] created
# KERNEL: Obj pkt[41] created
# KERNEL: Obj pkt[42] created
# KERNEL: Obj pkt[43] created
# KERNEL: Obj pkt[44] created
# KERNEL: Obj pkt[45] created
# KERNEL: Obj pkt[46] created
# KERNEL: Obj pkt[47] created
# KERNEL: Obj pkt[48] created
# KERNEL: Obj pkt[49] created
# KERNEL: -------- pkt[0-to-49].display() -----------
# KERNEL: No of Obj Created = 50
# KERNEL: -------- pkt[20].count_id = 20 -----------
# KERNEL: -------------------------------------------
Link : https://www.edaplayground.com/x/VPML
*/
//object assignment : example 5
class packet;
bit [7:0] addr;
bit [7:0] data;
bit rdn_wr;
function new();
addr=10;
data=10;
rdn_wr=0;
endfunction
function void display();
$display("------------------------------------------");
$display("\t addr = %0d",addr);
$display("\t data = %0d",data);
$display("\t rdn_wr = %0b",rdn_wr);
$display("------------------------------------------");
endfunction
endclass
module ex5;
packet pkt_1,pkt_2;
initial begin
pkt_1=new();
$display("--------------- pkt_1.display(); -----------");
pkt_1.display();
$display("--------------- pkt_2=pkt_1 ----------------");
pkt_2=pkt_1;
$display("--------------- pkt_2.display(); -----------");
pkt_2.display();
$display("--------------- pkt_2.addr=20 -----------");
pkt_2.addr=20;
$display("--------------- pkt_2.display(); -----------");
pkt_2.display();
$display("--------------- pkt_1.display(); -----------");
pkt_1.display();
end
endmodule
/* output
# KERNEL: --------------- pkt_1.display(); -----------
# KERNEL: ------------------------------------------
# KERNEL: addr = 10
# KERNEL: data = 10
# KERNEL: rdn_wr = 0
# KERNEL: ------------------------------------------
# KERNEL: --------------- pkt_2=pkt_1 ----------------
# KERNEL: --------------- pkt_2.display(); -----------
# KERNEL: ------------------------------------------
# KERNEL: addr = 10
# KERNEL: data = 10
# KERNEL: rdn_wr = 0
# KERNEL: ------------------------------------------
# KERNEL: --------------- pkt_2.addr=20 -----------
# KERNEL: --------------- pkt_2.display(); -----------
# KERNEL: ------------------------------------------
# KERNEL: addr = 20
# KERNEL: data = 10
# KERNEL: rdn_wr = 0
# KERNEL: ------------------------------------------
# KERNEL: --------------- pkt_1.display(); -----------
# KERNEL: ------------------------------------------
# KERNEL: addr = 20
# KERNEL: data = 10
# KERNEL: rdn_wr = 0
# KERNEL: ------------------------------------------
Link ; https://www.edaplayground.com/x/rAAQ
*/
// parameterised classes : example 8
class packet #(parameter ADDR_WIDTH=8,DATA_WIDTH=8);
rand bit [ADDR_WIDTH-1:0] addr;
rand bit [DATA_WIDTH-1:0] data;
function void display();
$display("----------------------------------");
$display("\t\t ADDR_WIDTH=%0d",ADDR_WIDTH);
$display("\t\t DATA_WIDTH=%0d",DATA_WIDTH);
$display("\t\t addr=%0d",addr);
$display("\t\t data=%0d",data);
$display("----------------------------------");
endfunction
endclass
module ex8;
packet #(8,8) pkt_1;
packet #(16,4) pkt_2;
initial begin
pkt_1 = new();
pkt_2 = new();
// ----- pkt_1
$display("------------ pkt_1.randomize() ---");
pkt_1.randomize(); // randomize addr and data
$display("------------ pkt_1.display() -----");
pkt_1.display();
// ----- pkt_2
$display("------------ pkt_2.randomize() ---");
pkt_2.randomize(); // randomize addr and data
$display("------------ pkt_2.display() -----");
pkt_2.display();
end
endmodule
/* output
# KERNEL: ------------ pkt_1.randomize() ---
# KERNEL: ------------ pkt_1.display() -----
# KERNEL: ----------------------------------
# KERNEL: ADDR_WIDTH=8
# KERNEL: DATA_WIDTH=8
# KERNEL: addr=164
# KERNEL: data=78
# KERNEL: ----------------------------------
# KERNEL: ------------ pkt_2.randomize() ---
# KERNEL: ------------ pkt_2.display() -----
# KERNEL: ----------------------------------
# KERNEL: ADDR_WIDTH=16
# KERNEL: DATA_WIDTH=4
# KERNEL: addr=53764
# KERNEL: data=5
# KERNEL: ----------------------------------
Link : https://www.edaplayground.com/x/bhmC
*/
// inheritance : example 9
class base;
rand bit [3:0] in;
rand bit [7:0] addr;
rand bit rdn_wr;
function void display();
$display("------------- BASE CLASS -------------");
$display("\t\t in = %0d",in);
$display("\t\t addr = %0d",addr);
$display("\t\t rdn_wr = %0b",rdn_wr);
$display("---------------------------------------");
endfunction
function void print();
$display("-- Inside print() from base class -------");
endfunction
endclass
class derive extends base;
rand bit [7:0] data;
function void display();
$display("------------- DERIVE CLASS -----------");
$display("\t\t data = %0d",data);
$display("---------------------------------------");
endfunction
endclass
module ex9;
base base_h;
derive derive_h;
initial begin
base_h = new();
derive_h = new();
$display("------------ base_h.randomize() ------");
base_h.randomize();
$display("------------ base_h.display() --------");
base_h.display();
$display("------------ base_h.print() ----------");
base_h.print();
$display("------------ derive_h.randomize() ----");
derive_h.randomize();
$display("------------ derive_h.display() ------");
derive_h.display();
$display("------------ derive_h.print() --------");
derive_h.print();
end
endmodule
/* output
# KERNEL: ------------ base_h.randomize() ------
# KERNEL: ------------ base_h.display() --------
# KERNEL: ------------- BASE CLASS -------------
# KERNEL: in = 8
# KERNEL: addr = 47
# KERNEL: rdn_wr = 0
# KERNEL: ---------------------------------------
# KERNEL: ------------ base_h.print() ----------
# KERNEL: -- Inside print() from base class -------
# KERNEL: ------------ derive_h.randomize() ----
# KERNEL: ------------ derive_h.display() ------
# KERNEL: ------------- DERIVE CLASS -----------
# KERNEL: data = 157
# KERNEL: ---------------------------------------
# KERNEL: ------------ derive_h.print() --------
# KERNEL: -- Inside print() from base class -------
Link : https://www.edaplayground.com/x/cJd2
*/
// override method ; example 10
class base;
function void display();
$display("---------------- BASE ----------");
$dipslay("**** inside base class *********");
$display("--------------------------------");
endfunction
endclass
class derive extends base;
function void display();
$display("---------------- DERIVE --------");
$dipslay("**** inside derive class *******");
$display("--------------------------------");
endfunction
endclass
module ex10;
base base_h;
derive derive_h;
initial begin
base_h =new();
derive_h=new();
$display("------------ base_h.display() ---");
base_h.display();
$display("------------ derive_h.display() -");
derive_h.display();
end
endmodule
/* output
# KERNEL: ------------ base_h.display() ---
# KERNEL: ---------------- BASE ----------
# KERNEL: --------------------------------
# KERNEL: ------------ derive_h.display() -
# KERNEL: ---------------- DERIVE --------
# KERNEL: --------------------------------
Link : https://www.edaplayground.com/x/qiXu
*/
// super keyword : example 11
class base;
bit [7:0] addr;
function new();
addr=10;
endfunction
function void display();
$display("--------------BASE--------------");
$display("\t\t addr=%0d",addr);
$display("--------------------------------");
endfunction
endclass
class derive extends base;
bit [7:0] data;
function new();
super.new();
data=20;
endfunction
function void display();
super.display();
$display("\t\t data=%0d ",data);
$display("--------------------------------");
endfunction
endclass
module ex11;
derive pkt;
initial begin
pkt=new();
$display("------------ pkt.display() ------");
pkt.display();
end
endmodule
/* output
KERNEL: ------------ pkt.display() ------
# KERNEL: --------------BASE--------------
# KERNEL: addr=10
# KERNEL: --------------------------------
# KERNEL: data=20
# KERNEL: --------------------------------
Link : https://www.edaplayground.com/x/vrwZ
*/
// data hiding : example 13
class base;
local int loop_count;
protected int count;
function new();
count=20;
endfunction
task set(int x);
loop_count=x;
endtask
function int get();
return loop_count;
endfunction
endclass
class derive extends base;
function void display();
$display("-------------------------------");
//$display("\t\t loop_count= %0d",loop_count);
$display("\t\t count = %0d",count);
$display("-------------------------------");
endfunction
endclass
module ex13;
derive derive_h;
initial begin
derive_h=new();
derive_h.set(20);
$display("--------- derive_h.get() = %0d ",derive_h.get());
$display("--------- derive_h.display() --");
derive_h.display();
end
endmodule
/* output
# KERNEL: --------- derive_h.get() = 100
# KERNEL: --------- derive_h.display() --
# KERNEL: -------------------------------
# KERNEL: count = 20
# KERNEL: -------------------------------
Link ; https://www.edaplayground.com/x/JSC9
*/
// virtual class : example 14_1
virtual class base;
static int count_id;
pure virtual function void display();
pure virtual function int return_count_id();
endclass
class derive extends base;
function void display();
$display("-------------------------------");
$display("Object created");
$display("-------------------------------");
endfunction
function new();
display();
count_id++;
endfunction
function int return_count_id();
return count_id;
endfunction
endclass
module ex14_1;
derive derive_h,derive_h1;
initial begin
derive_h = new();
derive_h1= new();
$display("No of obj created = %0d",derive_h.return_count_id());
end
endmodule
/* output
# KERNEL: -------------------------------
# KERNEL: Object created
# KERNEL: -------------------------------
# KERNEL: -------------------------------
# KERNEL: Object created
# KERNEL: -------------------------------
# KERNEL: No of obj created = 2
Link : https://www.edaplayground.com/x/tNgg
*/
// virtual functio/task : example 14_2
class base;
virtual function void display();
$display("------------- BASE_CLASS ------------");
$display("\t Inside base class");
$display("-------------------------------------");
endfunction
endclass
class derive extends base;
virtual function void display();
$display("------------- DERIVE_CLASS ----------");
$display("\t Inside derive class");
$display("-------------------------------------");
endfunction
endclass
module ex14_2;
base base_h;
derive derive_h;
initial begin
derive_h=new();
base_h=derive_h;
$display("--------- base_h.display() ----------");
base_h.display();
end
endmodule
/* output
# KERNEL: --------- base_h.display() ----------
# KERNEL: ------------- DERIVE_CLASS ----------
# KERNEL: Inside derive class
# KERNEL: -------------------------------------
Link : https://www.edaplayground.com/x/Ws72
*/
// extern keyword : example 15
class packet;
bit [7:0] addr;
extern function void display();
endclass
function void packet:: display();
$display("--------------------------------");
$display("\t\t addr=%0d",addr);
$display("--------------------------------");
endfunction
module ex15;
packet pkt;
initial begin
pkt=new();
pkt.addr=20;
pkt.display();
end
endmodule
/* output
# KERNEL: --------------------------------
# KERNEL: addr=20
# KERNEL: --------------------------------
Link : https://www.edaplayground.com/x/rGea
*/
Thank you for reading , have a nice day 😊😊.
