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RCOS C++ CRC for class port

Name:

 port

Comment:

 All Device drivers must be based on this Class. The constructor will be supplied with an ID and a pointer to a Knl class, which will handle message passing for the driver (normally the Kernel!) Drivers communicate by messages. These can be "posted" by calling the Knl class member "PostMsg" - which uses a FIFO queue to effect ascynchronous transfers, or by calling "SendMsg". This causes a direct (synchronous) transfer where the switcher directly invokes the recieve member of the distination port before returning to the sender. The actual message receiver is declared as a "pure virtual" meaning each instantiation MUST overload the function.

Collaborators:

Responsibilities:

 class port {
  public:
    UINT16 uID;                         // Unique ID of driver
    Knl   *pTx;                         // pointer to the message dispatcher
    port (UINT16, UINT16, Knl*);        // const. gets ID, class and Tx ptr
    void DevError (INT16, BOOL);        // Issue device error message
    virtual void RxPort (PMSG) = 0;     // Dispatcher for received messages
  };