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Ramarao V

how can i know which event triggered a process?

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Hi, All


there are 10 array of systemc events 

sc_event e[10]; 

and there is a systemc process which is sensitive above mentioned 10 events

my doubt is how can i know which event triggered my process

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Simple answer: there really is no straightforward way to do this. Of course if you wanted to get into the internals of the SystemC implementation, it is possible; however, that completely violates the standard.

As to why this is not allowed: performance. The desire to have efficiency overrides the desire for corner cases such as yours.

How can you work around this? Several possible approaches, but here one I would use:

 Create a new event class that adds tracking and an API to access it. This is easy to do if you know your C++ and SystemC well enough.

Trivial outline of concept::

static const sc_core::sc_process_handle NONEXISTANT;
struct Tracked_Event {
    void notify( void ); // sets m_process_handle and notifies m_event
    void notify( sc_core::sc_time delay ); // same except waits for delay
    sc_process_handle get_trigger( void ) { return m_process_handle; }
    void clear( void ) { m_process_handle = NONEXISTANT; };
    sc_core::sc_event    m_event;
    sc_core::sc_processhandle m_process_handle;
struct Event_array
    Event_array( int depth );
    void wait( void ); // clears all m_process on entry, then waits for an m_event
    Tracked_event operator[]( int );
    sc_vector<sc_core::sc_process_handle> get_trigger_list( void );
    sc_vector<Tracked_Event> m_event_array;
    sc_core::uint64          m_delta_count;


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SystemC 2.3.2 (and later) does support a query whether an event was triggered in the previous delta cycle (or immediately in the current evaluation cycle).  This is similar to the sc_signal<>::event() function.  With this, you can ask every element in your array, whether it was triggered and may have caused a wakeup of the process.  Of course, multiple events can have triggered simultaneously and will only cause a single wakeup of the process.

for( const auto ev& : e ) {
  if ( ev.triggered() ) {
    // ... 

Hope that helps,

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Responding to Phillip:

 I'm guessing this is coming up for the next update of the standard and is currently under consideration. I guess I need to find more time to get synced up to the latest additions since 2.3.

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