System Verilog Singleton Example

Purpose of a singleton:
To have a class which has only one instance(object)
All the objects of this class refer to same global object
that is created only once
This design pattern provides a mechanism for providing
namespaces to global variables

Download here. singleton-design-pattern
C++ example for singleton design pattern: click here

System Verilog example for singleton design pattern

// Filename  : singleton.sv
// Author    : A.G.Raja
// License   : GPL
// Website   : http://agraja.wordpress.com

module tb;

class Singleton;
// object that is created only once
extern static Singleton single;
// constructor that is called only once
extern function new;
// method to get object
extern function Singleton get_instance;
// data to check the functionality
int data;
endclass

initial Singleton::single = null;

function Singleton::new;
data = 14;
endfunction

function Singleton Singleton::get_instance;
// call the constructor for the first time
// if the object has been created already
// return reference to the object already created
if(single==null) single = new;
// return the reference to the object
return single;
endfunction

Singleton s, t;

initial begin
// don’t use s= new;
// since it will create new instances
// instead use the get_instance method
s = s.get_instance();
t = t.get_instance();
$display(“initial value of s.data  = “,s.data);
s.data = 25;
$display(“modified value of s.data = “,s.data);
$display(“value of t.data          = “,t.data);
end
endmodule

Result:
initial value of s->data  = 14
modified value of s->data = 25
value of t->data          = 25
Download here. singleton-design-pattern

C++ Singleton Example

Download here.  singleton-design-pattern

Purpose of a singleton:
To have a class which has only one instance(object)
All the objects of this class refer to same global object
that is created only once
This design pattern provides a mechanism for providing
namespaces to global variables

C++ example for singleton design pattern

// Filename  : singleton.cpp
// Author    : A.G.Raja
// License   : GPL
// Website   : http://agraja.wordpress.com

#include <iostream>

using namespace std;

class Singleton {
// constructor that is called only once
Singleton();
// object that is created only once
static Singleton *single;
public:
// method to get object
Singleton* get_instance();
// data to check the functionality
int data;
};

Singleton* Singleton::single = NULL;

Singleton* Singleton::get_instance() {
// call the constructor for the first time
// if the object has been created already
// return reference to the object already created
if(single==NULL) single = new Singleton();
return single;
}

Singleton::Singleton() {
data = 14;
}

int main() {
Singleton *s, *t ;
s = s->get_instance();
cout<<”initial value of s->data  = “<<s->data<<endl;
s->data = 25;
cout<<”modified value of s->data = “<<s->data<<endl;
t = t->get_instance();
cout<<”value of t->data          = “<<t->data<<endl;
}
// end of file singleton.cpp

Result:
initial value of s->data  = 14
modified value of s->data = 25
value of t->data          = 25

Download here.  singleton-design-pattern

System Verilog Virtual Interface

Download here. system_verilog_virtual_interface

// Filename    : virtual_interface.sv
// Author      : A.G.Raja
// License     : GPL
// Website     : http://agraja.wordpress.com

interface bus(input wire clk);
int address;
int data;

modport virtual_interface(input clk);
endinterface

module virtual_interface;
bit clk;
bus BUS(clk);
class monitor;
virtual bus VBUS;
task disp;
$display(VBUS.address);
$display(VBUS.data);
endtask
endclass
monitor m;

initial begin
m = new;
m.VBUS = BUS;
BUS.address = 100;
BUS.data    = 1234;
m.disp;
end
endmodule

// Running simulation in ncverilog
// ncverilog +sv virtual_interface.sv

// Running simulation in modelsim/questasim
// vlib work
// vlog -sv virtual_interface.sv
// vsim -c virtual_interface
// run

Download here. system_verilog_virtual_interface

Transaction Level Modeling in System Verilog

Download here. transactionlevelmodeling_systemverilog

// Filename    : tlm.sv
// Author      : A.G.Raja
// License     : GPL
// Website     : http://agraja.wordpress.com

module producer_consumer;

virtual class put_if;

// Abstract Class whose methods are not yet implemented
virtual task put(int val);
endtask
endclass

class producer;
put_if put_port;
task run;
int i;
for(i=0;i<10;i++) put_port.put(i);
endtask
endclass

class consumer extends put_if;

// methods of put_if class are over-ridden

// and defined here
task put(int val);
$display(“Consumer receiving “,val);
endtask
endclass

producer p;
consumer c;

initial begin
p = new;
c = new;
p.put_port = c;
p.run;
end
endmodule

// Running simulation in ncverilog

ncverilog +sv tlm.sv

// Running simulation in modelsim/questasim

vlib work

vlog -sv tlm.sv

vsim -c producer_consumer

run

Download here. transactionlevelmodeling_systemverilog

System Verilog OVM – Hello World Program

Here is hello world program in

System Verilog Open Verification Methodology

Download here. hello_ovm

// Filename : hello_ovm.sv

// Author : A.G.Raja

// License : GPL

// Website : http://agraja.wordpress.com

module hello_ovm;

`include “ovm.svh”

class Random extends ovm_transaction;

rand int num;

constraint c { num >= 0 && num < 50; }

function new(string name);

super.new(name);

endfunction

endclass

Random r;

initial begin

r = new(“Hello OVM”);

r.print();

ovm_report_message(“APPLIED ELECTRONICS JOURNAL”,

$psprintf(“Hello World”));

end

endmodule

// End of file hello_ovm.sv

One liner to run this in IUS

When OVM library is not installed by default:

1) Set OVMHOME to the root directory where OVM library is installed

setenv OVMHOME /netstar/ag.raja/sv/OVM/ovm-1.1

2.a) IUS 6.2-s003 and IUS 6.2-s004

irun -sv -nowarn PMBDVX -ovmhome $OVMHOME $OVMHOME/src/ovm_pkg.sv hello_ovm.sv

2.b) IUS 6.2-s005

irun -sv -ovmhome $OVMHOME $OVMHOME/src/ovm_pkg.sv hello_ovm.sv

When OVM is already installed to $CDS_INST_DIR/tools/ovm

a) IUS 6.2-s003 and IUS 6.2-s004

irun -sv -ovm -nowarn PMBDVX hello_ovm.sv

b) IUS 6.2-s005

irun -sv -ovm hello_ovm.sv

Using Options File

irun –f options_file

// options_file begins here

-sv

-ovm

hello_ovm.sv

// options_file ends here

Download here. hello_ovm

Syntax Highlight For System Verilog Files

Enable syntax highlight for sytemm verilog, verilog preprocessor files with extensions v, sv, vpp, svh, svhpp

Create a file named “.vimrc” in your home directory [*nix]

Put the following lines in that file

“File Begins here

“Note: Comments in vim script begin with double quote

“Filename : .vimrc

“Author    :  A.G.Raja

“Website  : http://agraja.wordpress.com

“Show line numbers

set nu

“Source the syntax file

so $VIMRUNTIME/syntax/verilog.vim

“Add file extensions to be highlighted

au Syntax sv runtime! syntax/verilog.vim

au Syntax svh runtime! syntax/verilog.vim

au Syntax vpp runtime! syntax/verilog.vim

au Syntax svpp runtime! syntax/verilog.vim

au Syntax svhpp runtime! syntax/verilog.vim

“End of file

C++ string, wstring conversion functions

Download here. string-wstring-conversion-functions

// Filename    : string_wstring.cpp
// Author      : A.G.Raja
// License     : GPL
// Website     : http://agraja.wordpress.com

#include <iostream>

using namespace std;

string wstring2string(wstring wstr) {
string str(wstr.length(),’ ‘);
copy(wstr.begin(),wstr.end(),str.begin());
return str;
}

wstring string2wstring(string str) {
wstring wstr(str.length(),L’ ‘);
copy(str.begin(),str.end(),wstr.begin());
return wstr;
}

int main() {
wstring wstr = string2wstring(“raja”);
string str = wstring2string(wstr);
cout<<str<<endl;
}

Download here. string-wstring-conversion-functions

Perl Script to Indent Verilog Files

Here’s a perl script to indent verilog files.

Download here. vindent.pdf

Add your own list of keywords to indent any source code

For example, this script could be used to indent C/C++/Java source codes.

This script uses two spaces for each indent.  This could be changed as required.

#!/usr/bin/perl
# Filename    : vindent.pl
# Author      : A.G.Raja
# Website     : http://agraja.wordpress.com
#
# Usage       : ./vindent.pl verilogfile.v
#             : ./vindent.pl *.*v*
# Help        : ./vindent.pl

# Verilog File indenter

# Space for each indent
my $Space = “  “;

# Block begin.  For indenting C/C++/Java program use “{“
my $Open = “begin”;
# Block end.  For indenting C/C++/Java program use “}”
my $Close = “end”;

# Block statements.
# Note: Each Open keyword must have corresponding Close keyword
my @Openkeywords = qw{ module program package interface class task function };
my @Closekeywords = qw{ endmodule endprogram endpackage endinterface endclass endtask endfunction };

sub indent {
my $indent = 0;
my($infile) = @_;
open(FILE, “$infile”) or die “Couldn’t open file \”$infile\”\n”;
open(TFILE, “>temp”) or die “Couldn’t create temp file\n”;

while($line = <FILE>) {
chomp $line;
$line =~ s/^\s*//;
print TFILE “$line \n”;
}
close TFILE;
close FILE;
open(TFILE, “<temp”);
open(FILE, “>$infile”);

while($line = <TFILE>) {
foreach $Closekey (@Closekeywords) {
if($line =~ /^$Closekey\s/) { $indent–; }
}
if (($line =~ /.*\s+$Close\s/ ) || ($line =~ /^$Close\s/))
{ $indent–; }
for($i=0;$i<$indent;$i++) { print FILE $Space; }
print FILE $line;
foreach $Openkey (@Openkeywords) {
if($line =~ /^$Openkey\s/) { $indent++; }
}
if (($line =~ /.*\s+$Open\s/ )|| ($line =~ /^$Open\s/))
{ $indent++; }
}
close FILE; close TFILE;
print “Indented File \”$infile\”\n”;
}

my $argnum;
if($ARGV[0] eq “”) {
print “Usage : vindent.pl verilogfile.v\n”;
print “        vindent.pl *.v\n”;
print “        vindent.pl *.*v*\n”;
print “Help  :\n”;
print “        vindent.pl\n”;
}
foreach $argnum (0 .. $#ARGV) {
my $ifile = $ARGV[$argnum];
&indent($ifile);
}
unlink “temp”;
Download here. vindent.pdf

C++ String Getline Class

Download here. getline

Features of the below string getline class

1) Can be used like getline function for streams

2) Can have multiple delimiters as opposed to the getline function for streams

3) Delimiter need not be single char. It can be a string

4) Pointer to current position in the string is automatically incremented

similar to that in stringstream

5) It is possible to rewind the pointer position to zero using the rewind() method.

6) It is also possible to get single char at the current position of pointer from the string

7) It is possible to get single char at current pointer position if it is one of the

characters of the list.  This is an optional argument to the get method

stream getline feature can be realized by calling the getline method of this

class without passing any arguments. No arguments to getline method defaults to

newline char as delimiter

// File : Getline.hh
// Author : A.G.Raja
// License : GPL
// Website : http://agraja.wordpress.com

#include <iostream>

using namespace std;

class Getline {
string text, buffer;
int pos,p;
public:
int str(string txt) {
pos = 0;
this->text = txt;
}
string getline(string delim = “\n”, int delim_type = 1);
char get(string delim = “”);
int unget(int decr = 1) {
pos -= decr;
}
int end() {
if(pos>=text.size()) return 1;
else return 0;
}
int rewind() {
pos = 0;
}
};

string Getline::getline(string delim, int delim_type) {
p = delim_type ? text.find(delim,pos)
: text.find_first_of(delim,pos);
if(p!=-1) {
buffer = text.substr(pos,p-pos);
pos = delim_type ? p+delim.length() : p +1;
} else {
buffer = text.substr(pos);
pos += buffer.length();
} return buffer;
}

char Getline::get(string delim) {
if(delim.empty() and pos<text.size()) return text[pos++];
if(delim.find(text[pos])!=-1) {
pos++;
return text[pos-1];
}
return 0; // must
}

// End of File Getline.hh

// File : test_Getline.cpp
// Author : A.G.Raja
// License : GPL
// Website : http://agraja.wordpress.com

#include <iostream>
#include “Getline.hh”

using namespace std;

int main() {
Getline g;
g.str(“Hi, my name is Raja\nI’m an Engineer”);
// Get the substring terminated by “y na”
cout<<g.getline(“y na”)<<endl;
// Result: “Hi, m”

// Get substring terminated by first of “sji”
cout<<g.getline(“sji”,0)<<endl;

// Get line terminated by ‘\n’
cout<<g.getline()<<endl;
// Result: “s Raja”

// Get single char at current position of pointer
cout<<g.get()<<endl;
// Result: “I”

// Get a char at current position of pointer
// if it is in the list “_$%’#”
cout<<g.get(“_$%’#”)<<endl;
// Result: “‘”

// Unget single char, unget 4 chars
g.unget(); g.unget(4);
}

Download here. getline

Perl script to display comments

Download here. c_help.pdf

 

#!/usr/bin/perl

# Filename: chelp.pl

# Author : A. G. Raja

# Website : agraja.wordpress.com

# License : GPL

# pass c file as argument to this script

# this script displays all the comments

use strict;

use warnings;

open(FILE,$ARGV[0]) or die “File not Found”;

my $line;

my $start=0;

while ( $line = <FILE> ) {

if($line =~ /\/\//)

{

$line=~ s/(.*)\/\/(.*)/$2/;

print $line;

}

if($line =~ /\/\*/)

{

$start=1;

$line=~ s/(.*)\/\*(.*)/$2/;

}

if($line =~ /\*\//)

{

$line=~ s/(.*)\*\//$1/;

print $line;

$start=0;

}

if($start) { print $line; }

}

close FILE;

 

Tips:

Use a shell script to redirect the output

of the above script to another program.

Example

#!/bin/bash

# Filename: help.sh

# Author : A.G.Raja

# Website : agraja.wordpress.com

# License : GPL

# rename chelp.pl to chelp

# Install chelp and add to path

chelp $1 | less

Demo:

 

Below is a C file

 

// Filename : demo.c

// Author : cfile.pl

// License : GPL

#include <stdio.h>

#define print(x) printf(“str=%s\n”,x);

int main(int argc, char **argv)

{

/* this is a multi-

line comment */

char *str=”File name:”;// this will print file name

print(argv[0])

return 0;

}

 

Type at the terminal:

[raja@agraja ]$ chelp demo.c

 

The following will be printed to stdout

 

Filename : demo.c

Author : cfile.pl

License : GPL

this is a multi-

line comment

this will print file name

Download here. c_help.pdf

C Find Replace Program

Download here. string_replace.pdf

// Filename : string_replace.c

// Author : A.G.Raja

// Website : agraja.wordpress.com

// License : GPL

#include <stdio.h>

 

 

char* string_replace(unsigned char *from, char *find, char *replace)

{

const char *p;

char *q, *to;

int i,d, match;

to=malloc(sizeof(char)*strlen(from)*strlen(replace)/strlen(find));

 

for(p = from, q = to; *p != ”; p++)

{

// find logic

for(d=0;d<strlen(find);d++)

{

if (*(p+d) == *(find+d)) match=1;

else match =0;

}

// replace logic

if (match)

{

for(i=0;i<strlen(replace);i++)

{

*(q+i)=*(replace+i);

}

q=q+i; p=p+d-1;

}

else // copy unchanged chars

{ *q=*p; q++; }

 

} *q = ”;

return to;

}

 

 

 

 

 

 

 

 

 

 

// Test code

int main()

{

unsigned char *str = “this is original text” ;

char f[]=”original”;

char r[]=”new”;

unsigned char *str2;

printf(“before:%s\n”,str);

str2=string_replace(str,f,r);

printf(“after:%s\n”,str2);

return 0;

}

 

Download here. string_replace.pdf

Tips:

See the following pages for char replace, trim spaces

char replace

trim spaces

 

C Find and Replace program

Download here. find_replace.pdf

// Filename : find_replace.c

// Author : A.G.Raja

// Website : agraja.wordpress.com

// License : GPL

#include <stdio.h>

void find_replace(char *to, unsigned char *from, char find, char replace)

{

const char *p; char *q;

for(p = from, q = to; *p != ”; p++)

{

if ( *p != find)

{ *q=*p; q++; }

else

{ *q=replace; q++; }

} *q = ”;

}

int main()

{

unsigned char *str = “this is original text” ;

unsigned char str2[strlen(str)];

printf(“before:%s\n”,str);

find_replace(str2,str,’s’,'x’);

printf(“after:%s\n”,str2);

return 0;

}

 

 

// This program can be used for single char only.

// string with more than one char is not supported

Download here. find_replace.pdf

Tips:

This function can be used to trim white spaces in file.

See this page for an example: Trim

See this page for string replace: string replace

 

 

 

 

Perl script to add Header to files

The following script will add text to the beginning of files.

Donwload here. perlheader.pdf

This is done in three steps

1) This script copies the contents of a file to local variable by slurping.

2) The necessary text that needs to be added at the beginning of the file is added.

3) Then the original contents of the file are added using the local variable.

 

 

#!/usr/bin/perl

# Filename: header.pl

# Author : A.G.Raja

# Website : agraja.wordpress.com

# License : GPL

# pass files as arguments to this script

# this script will add the header text

use strict;

use warnings;

sub addheader{

my($infile,$header)=@_;

my $text = do { local( @ARGV, $/ ) = $infile ; <> } ;

open(FILE,”>$infile”);

print FILE $header;

print FILE $text;

close FILE

}

my $argnum;

foreach $argnum (0 .. $#ARGV){

my $infile = $ARGV[$argnum];

# Edit line below to change header text

my $header = “Header line 1nHeader line 2nHeader line 3n”;

&addheader($infile,$header);

}

# chmod +x header.pl

# ./header.pl *.txt

 

Donwload here. perlheader.pdf

Perl Script to Generate Makefile

Download here. createmakefile.pdf

#!/usr/bin/perl
# File name: writemake.pl
# Author: A.G.Raja
# Website: agraja.wordpress.com
# License: GPL
 

use strict;
use warnings;
open(FH,">Makefile") or die "Cannot create Makefile";
print FH ("all: buildnn");
print FH ("build: " . $ARGV[0] .".onn");
print FH ("shared: " . $ARGV[0] . ".sonn");
print FH ("clean: n");
print FH ("trm ".$ARGV[0].".*o nn");

print FH ($ARGV[0].".o: ".$ARGV[0].".cn");
print FH ("tgcc -o ".$ARGV[0].".o ".$ARGV[0].".cnn");

print FH ($ARGV[0].".so: ".$ARGV[0].".cn");
print FH ("tgcc -fPIC -shared -o ".$ARGV[0].".so ".$ARGV[0].".cn");
close FH;
# Usage:
# chmod +x writemake.pl
# writenake.pl hello
 
Below is the Makefile generated:

all: build

build: hello.o

shared: hello.so

clean:
rm hello.*o

hello.o: hello.c
gcc -o hello.o hello.c

hello.so: hello.c
gcc -fPIC -shared -o hello.so hello.c

Download here. createmakefile.pdf

System Verilog DPI Example

Refer to the previous post for introduction.

System Verilog DPI NCVerilog

The above example gives a demo with NCVerilog.

Here is the run script for running the same example with Modelsim under windows.

Download here. system-verilog-dpi-modelsim.pdf

#File name run.tcl

# Author: A.G.Raja

# Website: agraja.wordpress.com

# License: GPL

#Type at Transcript terminal: source run.tcl

vlib work

vlog -sv -dpiheader dpiheader.h dpi_top.v

exec gcc -c -g -IE:/modelsim/include dpi_main.c -o dpi_main.obj

exec gcc -shared -o dpi_main.dll dpi_main.obj -LE:/modelsim/win32

vsim -novopt top -sv_lib dpi_main

run

# EOF run.tcl

Replace “E:/modelsim” with “modelsim installation path”

1) Don’t create a new project while starting Modelsim

2) Open and proceed directly to Modelsim.

3) At the transcript terminal change to the working directory

4) No need to create a folder named work.

5) The run script given above does it.

Download here. system-verilog-dpi-modelsim.pdf

Download NCVerilog demo here.
 systemverilogdpi.pdf

 

C/C++ Assertions

// assert.cpp

// Author: A.G.Raja

// Website: agraja.wordpress.com

// Licence: GPL

#include <iostream>

using namespace std;

#define my_assert(x) \

if(!x) cout<<__FILE__<<”:assertion on line “; \

cout<<__LINE__<<” failed”<<endl;

int main()

{

int a,b;

a=0;

my_assert(a) // User defined assertion

assert(a); // Predefined assertion

}

// g++ assert.cpp

Download here.

assert.doc

C++ File Operations

// file_write.cpp

// Author: A.G.Raja

// Website: agraja.wordpress.com

#include <iostream>

#include <fstream>

using namespace std;

int main () {

ofstream myfile (“example.txt”);

if (myfile.is_open())

{

myfile << “This is a line.\n”;

myfile << “This is another line.\n”;

myfile.close();

}

else cout << “Unable to open file”;

return 0;

}

// g++ file_write.cpp

// file_read.cpp

// Author: A.G.Raja

// Website: agraja.wordpress.com

#include <iostream>

#include <fstream>

#include <string>

using namespace std;

int main () {

string line;

ifstream myfile (“example.txt”);

if (myfile.is_open())

{

while (! myfile.eof() )

{

getline (myfile,line);

cout << line << endl;

}

myfile.close();

}

else cout << “Unable to open file”<<endl;

return 0;

}

//g++ file_read.cpp

Download here.

cpp_file_operations.doc

C++ Constructor Destructor

// constructor_destructor.cpp
// Author: A.G.Raja
// Website: agraja.wordpress.com
// Licence: GPL

#include <iostream>
using namespace std;
class Employee{
char *name;
int age;
double salary;
public: Employee(); //Constructor
void print();
void setval(char *name, int age, double salary);
char* getname() { return name; }
int getage() { return age; }
double getsalary() { return salary; }
~Employee(); //Destructor
};

Employee::Employee()
{
cout<<”Object Created”<<endl;
name=”fresher”;
age=23;
salary=17500;
}
void Employee::print()
{
cout<< name<<”\t”<<age<<”\t”<<salary <<endl;
}
void Employee::setval(char *n, int a, double s)
{
name=n;
age=a;
salary=s;
}

Employee::~Employee()
{
cout<<”Object Destroyed”<<endl;
}

int main()
{
char *NAME;
int AGE;
double SALARY;
//Employee E257 = {“raja”,25,23519.78};
Employee E257;
cout<<”Print Default Values”<<endl;
E257.print(); // Default Values
E257.setval(“raja”,25,23768);
cout<<”Print New Values”<<endl;
E257.print(); // New values
NAME=E257.getname();
AGE=E257.getage();
SALARY=E257.getsalary();
cout<<NAME<<”\t”<<AGE<<”\t”<<SALARY<<endl;
}
// g++ constructor_destructor.cpp

Download here.

constructor.doc

C++ struct vs class

This is an example to show the similarity between a struct and a class

  #include <iostream>using namespace std;

int main()

{

struct employee

{char *name;

int age;

double salary;

};

employee e257 = {”raja“,25,23519.78};

cout<< e257.name<<”\t”<<e257.age

<<”\t”<<e257.salary <<endl;

class Employee { public:      char *name;
     int age;double salary; };

Employee E257 = {”raja”,25,23519.78};

cout<< E257.name<<”\t”<<E257.age

<<”\t”<<E257.salary <<endl;

}

Note:
1) All members of a struct are public by default
2) All members of a class are private by default
3) For a class member to be public, it has be
declared public with the keyword "public".
Advantage of using classes
1) Member variables are private and protected.
2) Constructors functions(declared public) can be
used  to initialize and modify values of that private variables.
See this page for Constructors:  Constructors & Destructors </pre

 Download here.struct.doc

links for 2008-01-05

• System Verilog Language Reference Manual Changes/Errata
  System Verilog
  Changes
  LRM Changes
  (tags: System Verilog LRM Changes Errata)

links for 2008-01-04

• System Verilog String Methods Details
  System Verilog String Methods Details
  string to bin/hex/oct are defined as functions.
  bin/hex/oct to string are defined as tasks
  example usage:
  reg1=str1.atohex();
  bintoa.reg2(str2);
  (tags: bintoa hextoa octtoa atoi atohex atobin atoreal system verilog string methods type casting DPI)