vital_timing.vhdl

vhdl集成电路设计软件.需要用gcc-4.0.2版本编译.

    --                  are kept as is.
    --
    --                  The function is overloaded based on input type.
    --
    --                  There is no function to fill a 12 value delay
    --                  type.
    --
    -- Arguments:         
    --
    --  IN                 Type           Description
    --                     Delay          A one, two or six delay value Vital-
    --                                    DelayType is passed and a six delay,
    --                                    VitalDelayType01Z, item is returned.        
    --                    
    --  INOUT
    --   none
    --
    --  OUT
    --   none
    --
    --  Returns              
    --   VitalDelayType01Z
    --
    -- -------------------------------------------------------------------------
    FUNCTION VitalExtendToFillDelay (
            CONSTANT Delay : IN VitalDelayType
          ) RETURN VitalDelayType01Z;
    FUNCTION VitalExtendToFillDelay (
            CONSTANT Delay : IN VitalDelayType01
          ) RETURN VitalDelayType01Z;
    FUNCTION VitalExtendToFillDelay (
            CONSTANT Delay : IN VitalDelayType01Z
          ) RETURN VitalDelayType01Z;

    -- ------------------------------------------------------------------------
    --
    -- Function Name:   VitalCalcDelay
    --
    -- Description:     This function accepts a 1, 2 or 6 value delay and 
    --                  chooses the correct delay time to delay the NewVal 
    --                  signal.  This function is overloaded based on the
    --                  delay type passed. The function returns a single value
    --                  of time.
    --
    --                  This function is provided for Level 0 models in order
    --                  to calculate the delay which should be applied 
    --                  for the passed signal. The delay selection is performed
    --                  using the OldVal and the NewVal to determine the 
    --                  transition to select.  The default value of OldVal is X.
    --
    --                  This function cannot be used in a Level 1 model since
    --                  the VitalPathDelay routines perform the delay path
    --                  selection and output driving function.
    --
    -- Arguments:         
    --
    --  IN                 Type           Description
    --                      NewVal         New value of the signal to be
    --                                     assigned   
    --                      OldVal         Previous value of the signal.
    --                                     Default value is 'X'
    --                      Delay          The delay structure from which to
    --                                     select the appropriate delay.  The
    --                                     function overload is based on the
    --                                     type of delay passed.  In the case of
    --                                     the single delay, VitalDelayType, no
    --                                     selection is performed, since there
    --                                     is only one value to choose from.
    --                                     For the other cases, the transition
    --                                     from the old value to the new value
    --                                     decide the value returned.  
    --                    
    --  INOUT
    --   none 
    --
    --  OUT
    --   none
    --
    --  Returns              
    --   Time                              The time value selected from the
    --                                     Delay INPUT is returned.
    --
    -- -------------------------------------------------------------------------
    FUNCTION VitalCalcDelay (
            CONSTANT NewVal : IN std_ulogic   := 'X';
            CONSTANT OldVal : IN std_ulogic   := 'X';
            CONSTANT Delay  : IN VitalDelayType
          ) RETURN TIME;
    FUNCTION VitalCalcDelay (
            CONSTANT NewVal : IN std_ulogic   := 'X';
            CONSTANT OldVal : IN std_ulogic   := 'X';
            CONSTANT Delay  : IN VitalDelayType01
          ) RETURN TIME;
    FUNCTION VitalCalcDelay (
            CONSTANT NewVal : IN std_ulogic   := 'X';
            CONSTANT OldVal : IN std_ulogic   := 'X';
            CONSTANT Delay  : IN VitalDelayType01Z
          ) RETURN TIME;

    -- ------------------------------------------------------------------------
    --
    -- Function Name:   VitalPathDelay
    --
    -- Description:     VitalPathDelay is the Level 1 routine used to select
    --                  the propagation delay path and schedule a new output 
    --                  value.
    --
    --                  For single and dual delay values, VitalDelayType and
    --                  VitalDelayType01 are used.  The output value is
    --                  scheduled with a calculated delay without strength
    --                  modification.  
    --
    --                  For the six delay value, VitalDelayType01Z, the output       
    --                  value is scheduled with a calculated delay.  The drive 
    --                  strength can be modified to handle weak signal strengths
    --                  to model tri-state devices, pull-ups and pull-downs as
    --                  an example.
    --
    --                  The correspondence between the delay type and the
    --                  path delay function is as follows:
    --
    --                  Delay Type                Path Type
    --
    --                  VitalDelayType            VitalPathDelay
    --                  VitalDelayType01          VitalPathDelay01
    --                  VitalDelayType01Z         VitalPathDelay01Z
    --
    --                  For each of these routines, the following capabilities
    --                  is provided:
    --     
    --                  o Transition dependent path delay selection
    --                  o User controlled glitch detection with the ability
    --                    to generate "X" on output and report the violation
    --                  o Control of the severity level for message generation
    --                  o Scheduling of the computed values on the specified
    --                    signal.
    --                  
    --                  Selection of the appropriate path delay begins with the
    --                  candidate paths.  The candidate paths are selected by
    --                  identifying the paths for which the PathCondition is 
    --                  true.  If there is a single candidate path, then that
    --                  delay is selected.  If there is more than one candidate
    --                  path, then the shortest delay is selected using 
    --                  transition dependent delay selection.  If there is no 
    --                  candidate paths, then the delay specified by the 
    --                  DefaultDelay parameter to the path delay is used.
    --                  
    --                  Once the delay is known, the output signal is then
    --                  scheduled with that delay.  In the case of 
    --                  VitalPathDelay01Z, an additional result mapping of
    --                  the output value is performed before scheduling.  The
    --                  result mapping is performed after transition dependent
    --                  delay selection but before scheduling the final output.
    --                      
    --                  In order to perform glitch detection, the user is
    --                  obligated to provide a variable of VitalGlitchDataType
    --                  for the propagation delay functions to use.  The user
    --                  cannot modify or use this information.
    --
    -- Arguments:         
    --
    --  IN             Type                   Description
    --   OutSignalName  string                 The name of the output signal
    --   OutTemp        std_logic              The new output value to be driven
    --   Paths          VitalPathArrayType     A list of paths of VitalPathArray
    --                  VitalPathArrayType01   type.  The VitalPathDelay routine
    --                  VitalPathArrayType01Z  is overloaded based on the type
    --                                         of constant passed in.  With
    --                                         VitalPathArrayType01Z, the
    --                                         resulting output strengths can be
    --                                         mapped.
    --   DefaultDelay   VitalDelayType         The default delay can be changed  
    --                  VitalDelayType01       from zero-delay to another set of 
    --                  VitalDelayType01Z      values.   
    --   Mode           VitalGlitchKindType    The value of this constant
    --                                         selects the type of glitch
    --                                         detection.
    --                       OnEvent           Glitch on transition event
    --                     | OnDetect          Glitch immediate on detection
    --                     | VitalInertial     No glitch, use INERTIAL
    --                                         assignment
    --                     | VitalTransport    No glitch, use TRANSPORT 
    --                                         assignment
    --   XOn            BOOLEAN                Control for generation of 'X' on 
    --                                         glitch.  When TRUE, 'X's are
    --                                         scheduled for glitches, otherwise
    --                                         no are generated.             
    --   MsgOn          BOOLEAN                Control for message generation on
    --                                         glitch detect.  When TRUE,
    --                                         glitches are reported, otherwise
    --                                         they are not reported.      
    --   MsgSeverity    SEVERITY_LEVEL         The level at which the message,
    --                                         or assertion, will be reported. 
    --   OutputMap      VitalOutputMapType     For VitalPathDelay01Z, the output
    --                                         can be mapped to alternate
    --                                         strengths to model tri-state 
    --                                         devices, pull-ups and pull-downs.  
    -- 
    --  INOUT
    --   GlitchData     VitalGlitchDataType    The internal data storage
    --                                         variable required to detect
    --                                         glitches.
    --
    --  OUT
    --   OutSignal      std_logic              The output signal to be driven
    --
    --  Returns              
    --   none 
    --
    -- -------------------------------------------------------------------------
    PROCEDURE VitalPathDelay (
        SIGNAL   OutSignal     : OUT   std_logic;
        VARIABLE GlitchData    : INOUT VitalGlitchDataType;
        CONSTANT OutSignalName : IN    string;
        CONSTANT OutTemp       : IN    std_logic;
        CONSTANT Paths         : IN    VitalPathArrayType;
        CONSTANT DefaultDelay  : IN    VitalDelayType      := VitalZeroDelay;
        CONSTANT Mode          : IN    VitalGlitchKindType := OnEvent;
        CONSTANT XOn           : IN    BOOLEAN             := TRUE;
        CONSTANT MsgOn         : IN    BOOLEAN             := TRUE;
        CONSTANT MsgSeverity   : IN    SEVERITY_LEVEL      := WARNING