TrgPeriodic.py

#!/usr/local/bin/python
#
#                               Copyright 2004
#                                     by
#                        The Board of Trustees of the
#                     Leland Stanford Junior University.
#                            All rights reserved.
#

__facility__ = "Online"
__abstract__ = "GLAST LAT Trigger Periodic Interface classes"
__author__   = "M. Huffer <mehsys@slac.stanford.edu> SLAC - GLAST LAT Electronics"
__date__     = "1/14/04"
__version__  = "$Revision: 2.1 $"
__release__  = "$Name: R04-12-00 $"
__credits__  = "SLAC"

import LATTE.copyright_SLAC


from TrgObject import TrgObject


"""TrgPeriodic: Interface for the Periodic Trigger"""

class TrgPeriodicConditionAbstract(TrgObject):
  """\brief TrgPeriodicConditionAbstract class definition
  """
  def __init__(self):
    """\brief TrgPeriodicConditionAbstract constructor
    """
    pass

  def source(self):
    """\brief source() 'virtual' method
    If the returned value is FALSE, the system clock is used as the
    source of the periodic condition. If the returned value is TRUE, the 1-PPS signal is
    used as the source of the condition.
    \return A boolean
    """
    raise NotImplementedError
    pass

  def prescale(self):
    """\brief prescale() 'virtual' method
    Determines how the source signal is prescaled to form the periodic condition.
    That is, it sets the rate of the periodic condition. A value of zero does not prescale
    the periodic condition. This would, for example, assuming the system clock is
    used as source, create a periodic condition which operates at 20 MHZ.
    Range: [0 .. 0xffffff]
    \return An integer
    """
    raise NotImplementedError
    pass
  
  def limit(self):
    """\brief limit() 'virtual' method
    Returns the number of iterations of the periodic condition before
    the condition stops. A value of zero (0) will cause the periodic condition to
    'free-run', or never stop.
    \return An integer
    """
    raise NotImplementedError
    pass

class TrgPeriodicCondition(TrgPeriodicConditionAbstract):
  """\brief Trigger Periodic Condition class definition
  """

  def __init__(self): # constructor...
    TrgPeriodicConditionAbstract.__init__(self)
    
  def definition(self):
    """\brief definition() method
    Returns an object of type TrgPeriodicConditionDefinition. 
    This object will be used to both define the initial values for the
    periodic condition and is used by the reset() function to re-establish
    the initial limit value.
    """
    raise NotImplementedError
    pass # returns an object of type TrgPeriodicConditionDefinition
    
  def remaining(self):
    """\brief remaining() method
    Returns the number of iterations remaining before the periodic condition stops.
    """
    raise NotImplementedError
    pass # returns an integer...
    
  def reset(self):
    """\brief reset() method
    Will cause the periodic condition to stop, regardless of how many iterations are
    remaining. It will re-initialize the limit function with the value returned by the
    limit function of. If the periodic condition is free running, this function has no
    effect.
    """
    raise NotImplementedError
    pass # returns void...
    
  def abort(self):
    """\brief abort() method
    Will cause the periodic condition to stop, regardless of how many iterations are
    remaining. If the periodic condition is free running, this function has no effect.
    """
    raise NotImplementedError
    pass # returns void...

class TrgPeriodicConditionDefinition(TrgPeriodicConditionAbstract):
  """\brief TrgPeriodicConditionDefinition class definition
  """
  def __init__(self):
    TrgPeriodicConditionAbstract.__init__(self)
    

class TrgDefaultPeriodicCondition(TrgPeriodicConditionDefinition):
  """\brief TrgDefaultPeriodicCondition class definition
  """
  def __init__(self):
    TrgPeriodicConditionDefinition.__init__(self)

  def source(self):
    """\brief source() method
    Default is FALSE, do not use 1-PPS clock
    """
    return False
    
  def prescale(self):
    """\brief prescale() method
    Default is 0x1fffff, 10 hz periodic function
    """
    # Generate a 10 hz periodic function
    # 20 Megahertz clock, 1fffff = 2e6
    return 0x1fffff
    
  def limit(self):
    """\brief limit() method
    Default is 0, free-run the condition.
    """
    return 0x0

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