simple_lookup.adb

基于MATLAB的simple_lookup详解

               return;
            end if;
         end loop;
      end;
   exception
      when E : others =>
         if ssGetErrorStatus(S) = "" then
            ssSetErrorStatus(S,
                             "Exception occured in mdlCheckParameters. " &
                             "Name: " & Exception_Name(E) & ", " &
                             "Message: " & Exception_Message(E) & " and " &
                             "Information: " & Exception_Information(E));
         end if;
   end mdlCheckParameters; -----------------------------------------------------


   -- Procedure: mdlInitializeSizes --------------------------------------------
   -- Abstract::
   --      Configure this S-Function block's attrubutes.
   --
   procedure mdlInitializeSizes(S : in SimStruct) is
   begin

      -- The X and Y values can be changed during simulation
      ssSetParameterTunable(S, X_VALUES_PRM_IDX,   TRUE);
      ssSetParameterName(S, X_VALUES_PRM_IDX,   "XValues");

      ssSetParameterTunable(S, Y_VALUES_PRM_IDX,   TRUE);
      ssSetParameterName(S, Y_VALUES_PRM_IDX,   "YValues");

      -- Lookup method parameter cannot be changed once simulation starts
      ssSetParameterTunable(S, LOOKUP_MTH_PRM_IDX, FALSE);
      ssSetParameterName(S, LOOKUP_MTH_PRM_IDX, "LookupMethod");

      -- Set Size Information
      ssSetNumContStates(S, 0);

      -- This S-Function has one input port
      ssSetNumInputPorts(             S, 1);

      -- Set the input port attributes
      ssSetInputPortWidth(            S, 0, DYNAMICALLY_SIZED);
      ssSetInputPortDataType(         S, 0, SS_DOUBLE);
      ssSetInputPortDirectFeedThrough(S, 0, TRUE);
      ssSetInputPortOptimizationLevel(S, 0, 3);
      ssSetInputPortOverWritable(     S, 0, TRUE);

      -- This S-Function has two output ports
      ssSetNumOutputPorts(            S, 2);

      -- The first output port signal is the looked up table value
      ssSetOutputPortWidth(           S, 0, DYNAMICALLY_SIZED);
      ssSetOutputPortDataType(        S, 0, SS_DOUBLE);
      ssSetOutputPortOptimizationLevel(S, 0, 3);

      -- The second output port signal is the index into table corresponding to
      -- the looked up value.  In addition,  the lookup algorithm uses the last
      -- index to start search,  so the last index value has  to be persistent,
      -- hence mark this signal as not reusable
      ssSetOutputPortWidth(           S, 1, DYNAMICALLY_SIZED);
      ssSetOutputPortDataType(        S, 1, SS_INT32);
      ssSetInputPortOptimizationLevel(S, 0, 0);

      -- Set the block sample time
      ssSetSampleTime(S, INHERITED_SAMPLE_TIME);
   exception
      when E : others =>
         if ssGetErrorStatus(S) = "" then
            ssSetErrorStatus(S,
                             "Exception occured in mdlInitializeSizes. " &
                             "Name: " & Exception_Name(E) & ", " &
                             "Message: " & Exception_Message(E) & " and " &
                             "Information: " & Exception_Information(E));
         end if;
   end mdlInitializeSizes; -----------------------------------------------------


   -- Procedure: mdlStart ------------------------------------------------------
   -- Abstract::
   --      Initialize block specific data at simulation start. For this block,
   --      this involves setting the persistent output to a reasonable value.
   --      Note that we should (and need) not initialize the first output port
   --      signal because it is not persistent, and to correctly initialize it
   --      we need to know the value of the input signal, which is not available
   --      at this point.
   --
   procedure mdlStart(S : in SimStruct) is
      Y1Width : Integer := ssGetOutputPortWidth(S,1);
      Y1      : array(0 .. Y1Width-1) of Int_T;
      for Y1'Address use ssGetOutputPortSignalAddress(S,1);

      MidPoint : Integer := (ssGetParameterWidth(S,0)+1)/2;
   begin
      -- Initalize the second output port signal, which holds the
      -- index into the lookup table, to the middle of the table.
      for I in 0 .. Y1Width-1 loop
         Y1(I) := MidPoint;
      end loop;
   exception
      when E : others =>
         if ssGetErrorStatus(S) = "" then
            ssSetErrorStatus(S,
                             "Exception occured in mdlStart. " &
                             "Name: " & Exception_Name(E) & ", " &
                             "Message: " & Exception_Message(E) & " and " &
                             "Information: " & Exception_Information(E));
         end if;
   end mdlStart; ---------------------------------------------------------------


   -- Procedure: mdlOutputs ----------------------------------------------------
   -- Abstract::
   --      Compute the block output port signals. Note that this is just a
   --      "wrapper" function.  The actual algorithms are implemented in a
   --      seperated package "lookup_methods", which is accessed both from
   --      here and Ada code generated using the RTW Ada Code.
   --
   procedure mdlOutputs(S : in SimStruct; TID : in Integer) is
      BlockWidth : Integer := ssGetInputPortWidth(S,0);

      U  : array(0 .. BlockWidth-1) of Standard.Long_Float;
      for U'Address use ssGetInputPortSignalAddress(S,0);

      Y0 : array(0 .. BlockWidth-1) of Standard.Long_Float;
      for Y0'Address use ssGetOutputPortSignalAddress(S,0);

      Y1 : array(0 .. BlockWidth-1) of Integer;
      for Y1'Address use ssGetOutputPortSignalAddress(S,1);

      TableLength : Integer := ssGetParameterWidth(S, X_VALUES_PRM_IDX);

      XVal  : array(1 .. TableLength) of Standard.Long_Float;
      for XVal'Address use ssGetParameterAddress(S, X_VALUES_PRM_IDX);

      YVal  : array(0 .. TableLength) of Standard.Long_Float;
      for YVal'Address use ssGetParameterAddress(S, Y_VALUES_PRM_IDX);

      LookupMth : String := ssGetStringParameter(S, LOOKUP_MTH_PRM_IDX);
   begin

      if LookupMth = "left" then
         Lookup_Methods.Left_Continuous_Lookup(Lookup_Methods.Dbl_Array(U),
                                               Lookup_Methods.Dbl_Array(Y0),
                                               Lookup_Methods.Int_Array(Y1),
                                               Lookup_Methods.Dbl_Array(XVal),
                                               Lookup_Methods.Dbl_Array(YVal));
      elsif LookupMth = "right" then
         Lookup_Methods.Right_Continuous_Lookup(Lookup_Methods.Dbl_Array(U),
                                                Lookup_Methods.Dbl_Array(Y0),
                                                Lookup_Methods.Int_Array(Y1),
                                                Lookup_Methods.Dbl_Array(XVal),
                                                Lookup_Methods.Dbl_Array(YVal));
      else
         ssSetErrorStatus(S, "Unexpected parameter value " & LookupMth &
                          " encountered in mdlOutputs");
      end if;

   exception
      when Lookup_Methods.Algorithm_Error =>
         ssSetErrorStatus(S, "Algorithmic error in Lookup_Methods");
      when E : others =>
         if ssGetErrorStatus(S) = "" then
            ssSetErrorStatus(S,
                             "Exception occured in mdlOutputs. " &
                             "Name: " & Exception_Name(E) & ", " &
                             "Message: " & Exception_Message(E) & " and " &
                             "Information: " & Exception_Information(E));
         end if;
   end mdlOutputs; -------------------------------------------------------------

end Simple_Lookup;

-- EOF: simple_lookup.adb