Primitives Management
---------------------

New primitives library can be added. The primitives library is a python script.

.. code-block:: python

  import snl

  # define a combinatorial AND2 Primitive with:
  # - 2 scalar inputs: I0 and I1
  # - 1 scalar output: O
  def constructAND2(lib):
    and2 = snl.SNLDesign.createPrimitive(lib, "AND2")
    i0 = snl.SNLScalarTerm.create(and2, snl.SNLTerm.Direction.Input, "I0")
    i1 = snl.SNLScalarTerm.create(and2, snl.SNLTerm.Direction.Input, "I1")
    o = snl.SNLScalarTerm.create(and2, snl.SNLTerm.Direction.Output, "O")
    snl.SNLDesign.addCombinatorialArcs([i0, i1], o)

  # define a sequential FD Primitive with:
  # - 1 scalar input: D, 1 scalar clock input: C
  # - 1 scalar output: Q
  # - 1 a binary parameter "MASK" of size 1 with default value "0b0" 
  def constructFD(lib):
    fd = snl.SNLDesign.createPrimitive(lib, "FD")
    q = snl.SNLScalarTerm.create(fd, snl.SNLTerm.Direction.Output, "Q")
    c = snl.SNLScalarTerm.create(fd, snl.SNLTerm.Direction.Input, "C")
    d = snl.SNLScalarTerm.create(fd, snl.SNLTerm.Direction.Input, "D")
    snl.SNLParameter.create_binary(fd, "MASK", 1, 0b0)
    snl.SNLDesign.addInputsToClockArcs(d, c)
    snl.SNLDesign.addClockToOutputsArcs(c, q)

  #The "primitives" script needs to define a constructPrimitives function
  # taking a primitives library to construct.
  def constructPrimitives(lib):
    constructAND2(lib)
    constructREG(lib)