Verification Using SystemC Part II

Using the scv_extensions_if

The abstract methods provided by scv_extensions_if can be classified into methods for static extensions and methods for dynamic extensions. A static extension is used for simple type information and value access or assignment. This is accomplished via the scv_get_extensions() function in the Verification Standard.

The target list of data types supported by the data introspection facility is shown in the following table.

Data Type	Partial Template Specialization
bool	class scv_extensions<bool>
char	class scv_extensions<char>
short	class scv_extensions<short>
int	class scv_extensions<int>
long	class scv_extensions<long>
long long	class scv_extensions<long long>
unsigned char	class scv_extensions<unsigned char>
unsigned short	class scv_extensions<unsigned short>
unsigned int	class scv_extensions<unsigned int>
unsigned long	class scv_extensions<unsigned long>
unsigned long long	class scv_extensions<unsigned long long>
float	class scv_extensions<float>
double	class scv_extensions<double>
string	class scv_extensions<string>
pointer	class scv_extensions<T*>
array	class scv_extensions<T[N]>
sc_string	class scv_extensions<sc_string>
sc_bit	class scv_extensions<sc_bit>
sc_logic	class scv_extensions<sc_logic>
sc_int	template<int W> class scv_extensions< sc_int<W> >
sc_uint	template<int W> class scv_extensions< sc_uint<W> >
sc_bigint	template<int W> class scv_extensions< sc_bigint<W> >
sc_biguint	template<int W> class scv_extensions< sc_biguint<W> >
sc_bv	template<int W> class scv_extensions< sc_bv<W> >
sc_lv	template<int W> class scv_extensions< sc_lv<W> >
sc_fixed	template<int W, int I, sc_q_mode Q, sc_o_mode O, int N> class scv_extensions< sc_fixed<W,I,Q,O,N> >
sc_ufixed	template<int W, int I, sc_q_mode Q, sc_o_mode O, int N> class scv_extensions< sc_ufixed<W,I,Q,O,N> >

These template specializations include appropriate operators so that they behave as if they are the underlying data objects. For example, most of them include the operators +=, -=, *=, /=, %=, ^=, etc., and the specializations for integer types include operators ++, --, <<=, and >>=. The specializations for SystemC types include the corresponding methods in the underlying object, such as to_int64(). These operators are required to support value change callbacks, etc. Implicit conversion to the underlying data type is used whenever possible. Similar to read() and write() in a SystemC port (sc_port), these extension classes also have read() and write() to get around the implicit conversion problem. In most cases, the C++ compiler can perform the implicit conversion automatically. In the cases when the compiler cannot deduce the right conversion, read() and write() can be used. Another method called get_instance() returns a non-constant pointer to the underlying object; this method must be used in conjunction with another method trigger_value_change_cb() to make sure value change callbacks are executed correctly. Data introspection is useful only

Example : scv_extensions_if


  1 #include <scv.h>
  2 
  3 int sc_main (int argc, char* argv[]) {
  4   // Int data type
  5   int data = 100; 
  6   // Get the bitwidth of the data
  7   int bitwidth = scv_get_extensions(data).get_bitwidth();
  8   cout << "Width of data is "<< bitwidth << endl;
  9   cout << "Value in data is ";
 10   // Get the value in data and print to stdio
 11   scv_get_extensions(data).print();
 12   return 0;
 13 }

You could download file scv_extensions.cpp here

Simulation Output : scv_extensions_if

 Width of data is 32
 Value in data is 100

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