source: sources/src/sc_signal.h @ 58

/*------------------------------------------------------------\
|                                                             |
| Tool    :                  systemcass                       |
|                                                             |
| File    :                   sc_signal.h                     |
|                                                             |
| Author  :                 Buchmann Richard                  |
|                           Taktak Sami                       |
|                                                             |
| Date    :                   09_07_2004                      |
|                                                             |
\------------------------------------------------------------*/

#ifndef __SC_SIGNAL_H__
#define __SC_SIGNAL_H__

// Define registers writing method
#include <iostream>
#include <cstdlib>

#include "sc_fwd.h"
#include "sc_nbdefs.h"
#include "sc_time.h" // SC_ZERO_TIME
#include "sc_object.h"
#include "sc_interface.h"
#include "internal_ext.h"

namespace sc_core {

//
#if ((__GNUC__ < 3) || (__GNUC_MINOR__ < 4))
    #define INLINE __attribute__((always_inline))
#else
    /* gcc3.4 doesn't support */ 
    #define INLINE
#endif


#define READ_SIGNAL(value_type_,pointer_) \
    ((value_type_ &) (*((value_type_ *) (pointer_))))

///////////////////// DEPRECATED
// C ANSI-only since it is needed to link with extern "C"

extern void bind(sc_port_base &, sc_port_base &);
extern void bind(sc_port_base &, sc_signal_base &);
extern void bind(sc_signal_base & x);
extern void bind(sc_port_base & x);

typedef tab_t base_type;

struct pending_write_t {
    base_type * pointer;
    base_type value;
    //pending_write_t(base_type * const pointer_, const base_type value_) {
    //    pointer = pointer_;
    //    value = value_;
    //}
    
    friend std::ostream & operator << (std::ostream & o, const pending_write_t & p) {
        return o << "(pointer = " << p.pointer << "; value = " << p.value << ")\n";
    }
};


// Check pending_writing to register
extern void pending_writing2register_clear();
extern void pending_writing2register_record_and_check(const tab_t *);

// Pending write to register (simple stack)
typedef pending_write_t * pending_write_vector_t;
extern pending_write_vector_t pending_write_vector;
extern "C" unsigned int pending_write_vector_nb;
extern unsigned int pending_write_vector_capacity;


template < typename T >
inline void post_write(base_type * const pointer_, const T value_) /*INLINE*/;

template < typename T >
inline void post_multiwrite(base_type * const pointer_, const T value_) {
    size_t size = (sizeof(T) - 1) / sizeof(base_type);
    size_t i = 0;
    const base_type * pvalue = (const base_type *) (void *) (& value_);
    do {
        post_write(pointer_ + i, pvalue[i]);
    } while (i++ < size);
}

template < typename T >
inline void post_write(base_type * const pointer_, const T value_) {
    if (sizeof(T) > sizeof(base_type)) {
        post_multiwrite(pointer_,value_);
    }
    else {
#if defined(CONFIG_DEBUG)
        if (pending_write_vector_nb >= pending_write_vector_capacity) {
            std::cerr << "Error : The array for posted writing on register is too small.\n";
            std::cerr << "Up to 1 writing per register is allowed during a cycle.\n";
            std::cerr << "Please check the hardware description.\n";
            exit(-1);
        }
#endif
        pending_write_vector[pending_write_vector_nb].pointer = pointer_;
        // pending_write_vector[pending_write_vector_nb++].value = *(reinterpret_cast<const base_type*const>(&value_)); => bug !
        pending_write_vector[pending_write_vector_nb++].value = value_; // => bug avec blues !

        // -> fix to use user-defined struct in sc_signal/sc_in/sc_out/sc_inout
        // pending_write_vector[pending_write_vector_nb++].value = *((base_type*)&value_); => bug !
#if 0
        std::cerr << "posted write : ptr = " << pointer_ << ", val = " << value_ << "\n";
#endif
#if 0 
        // introduce bug on using trace functions
        if (value_ == READ_SIGNAL(T,pointer_)) {
            return;
        }
#endif
    }
}


inline bool is_posted_write() {
    return pending_write_vector_nb > 0;
}


extern "C" void update(void);


// ----------------------------------------------------------------------------
//  CLASS : sc_signal_base
//
//  The sc_signal_base<T> primitive channel class.
// ----------------------------------------------------------------------------

class sc_signal_base : public sc_object, public sc_interface {

    //////
    // Internal
    friend class sc_clock;
    friend class sc_port_base;
    void init();
    ////// 


    public: 
    // LRM (?)
    //virtual const sc_event /*&*/ default_event() const;
    static const char * const kind_string;
    //virtual const char * kind() const;

    

    public:
    sc_signal_base();
    sc_signal_base(const char * name_);
    sc_signal_base(const char * name_, void *);
    ~sc_signal_base();

};


template < typename T >
class sc_signal : public sc_signal_base {

    private:
    T val;
    typedef T data_type;
    typedef sc_signal < T > this_type;


    ///////////
    // Internal
    public:
    void init();
    ///////////

    void check_writer();

    public:
    // constructors, destructor 
    sc_signal() {
        init();
    }

    explicit sc_signal(const char * name_) : sc_signal_base(name_) {
        init();
    }

    /*virtual*/ ~sc_signal() {}
    /*virtual*/ inline const data_type & read() const INLINE;
    /*virtual*/ inline void write(const data_type &) /*INLINE*/;

    inline operator const data_type & () const { return this->read(); }

    inline this_type & operator = (const data_type & a) {
        sc_signal< T >::write(a);
        return *this;
    }

    inline this_type & operator = (const sc_signal < T > & a) {
        sc_signal< T >::write(a.read());
        return *this;
    }

    inline this_type & operator += (const data_type & a) {
        sc_signal< T >::write(read() + a);
        return *this;
    }

    inline this_type & operator += (const sc_signal < T > & a) {
        sc_signal< T >::write(read() + a.read());
        return *this;
    }

    const data_type & get_new_value() const;

    //  void trace (sc_trace_file * tf) const;
    /*
    virtual void print(std::ostream & o) const { o << *this; }
    virtual void dump(std::ostream & o) const { o << *this; }
    */

    private:
    // disabled 
    sc_signal(const sc_signal < T > &);

};


template < typename T >
void sc_signal< T >::init() {
    set_pointer((tab_t *) (void *) &val);
    set_kind(kind_string);
    sc_interface::init(sizeof(data_type)); 
    val = 0; /* The simulator initializes the signal/register to 0.    */
    /* However, hardware initialization still has to be done. */
    /* This kind of initialization is for trace diffing.      */
}


// read the value
template < typename T >
/*virtual*/ inline const T & sc_signal< T >::read() const {
#ifdef DUMP_READ
    std::cerr << "read " << READ_SIGNAL(const T, get_pointer()) << " on signal " << name() << "\n";
#endif
    return READ_SIGNAL(const T, get_pointer());
}


// write the new value
template < typename T >
inline void sc_signal< T >::write(const data_type & value_) {
#ifdef CONFIG_DEBUG
    if (get_pointer() == NULL) {
        std::cerr << "Error : Unable to write into '" << name() << "'.";
        exit(24032005);
    }
#endif
#ifdef DUMP_WRITE
    if (sc_signal< T >::read() == value_) {
        return;
    }
    std::cerr << "write (posted) " << value_ << " on sc_signal (writing into register) '" << name() << "'\n";
#endif
    post_write(/*(tab_t*)&val*/ get_pointer(), value_);
}

#undef INLINE
#undef READ_SIGNAL


} // end of namespace sc_core

#endif /* __SC_SIGNAL_H__ */

/*
# Local Variables:
# tab-width: 4;
# c-basic-offset: 4;
# c-file-offsets:((innamespace . 0)(inline-open . 0));
# indent-tabs-mode: nil;
# End:
#
# vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=4:softtabstop=4
*/