class Xor:
def __init__(self):
# components:
self.not1 = Not()
self.not2 = Not()
self.and1 = And()
self.and2 = And()
self.or1 = Or()
# connections:
self.a = self.and1.a
self.not2.a = self.and1.a
self.b = self.and2.b
self.not1.a = self.and2.b
self.and1.b = self.not1.x
self.and2.a = self.not2.x
self.or1.a = self.and1.x
self.or1.b = self.and2.x
self.x = self.or1.x
def update(self):
self.not1.update()
self.not2.update()
self.and1.update()
self.and2.update()
self.or1.update()
def derive(self, s):
left = self.children[0]
right = self.children[1]
if left.containsEpsilon():
orChildren = []
orChildren.append(Concat.getERE(left.derive(s), right.__copy__()))
orChildren.append(right.derive(s))
return Or.getERE(orChildren)
return Concat.getEre(left.derive(s), right.__copy__())
def derive(self, s):
left = self.children[0]
right = self.children[1]
if left.containsEpsilon():
orlist = [
Concat.getERE(left.derive(s), right.__copy__()),
right.derive(s)
]
return Or.getERE(orlist)
return self.getERE(left.derive(s), right.__copy__())
def Ifxtheny(a, b, z):
notx = Signal(0)
out = Signal(0)
n1 = Not(a, notx)
n2 = Or(notx, b, out)
@always_comb
def f():
z.next = out
return f, n1, n2
def Nor(a, b, z):
orab = Signal(0)
out = Signal(0)
n1 = Or(a, b, orab)
n2 = Not(orab, out)
@always_comb
def f():
z.next = out
return f, n1, n2
def Ifythenx(a, b, z):
noty = Signal(0)
out = Signal(0)
n1 = Not(b, noty)
n2 = Or(noty, a, out)
@always_comb
def f():
z.next = out
return f, n1, n2
def Ifxtheny(x, y, out):
out1 = Signal(0)
n1 = Signal(0)
n2 = Signal(0)
n3 = Signal(0)
n4 = Signal(0)
n5 = Signal(0)
n6 = Signal(0)
s1 = Not(x, n3)
s2 = Or(n3, y, out1)
@always_comb
def f():
out.next = out1
return f, s1, s2
def Nor(x, y, out):
out1 = Signal(0)
n1 = Signal(0)
n2 = Signal(0)
n3 = Signal(0)
n4 = Signal(0)
n5 = Signal(0)
n6 = Signal(0)
s1 = Or(x, y, n1)
s2 = Not(n1, out1)
@always_comb
def f():
out.next = out1
return f, s1, s2
def Xor(x, y, out):
out1 = Signal(0)
n1 = Signal(0)
n2 = Signal(0)
n3 = Signal(0)
n4 = Signal(0)
n5 = Signal(0)
n6 = Signal(0)
s1 = Xandnoty(x, y, n3)
s2 = Notxandy(x, y, n6)
s3 = Or(n3, n6, out1)
@always_comb
def f():
out.next = out1
return f, s1, s2, s3
def Equivalence(a, b, z):
notx = Signal(0)
noty = Signal(0)
andxy = Signal(0)
andnotxnoty = Signal(0)
out = Signal(0)
n1 = Not(a, notx)
n2 = Not(b, noty)
n3 = And(a, b, andxy)
n4 = And(notx, noty, andnotxnoty)
n5 = Or(andxy, andnotxnoty, out)
@always_comb
def f():
z.next = out
return f, n1, n2, n3, n4, n5
def Xor(a, b, z):
nota = Signal(0)
notb = Signal(0)
andanotb = Signal(0)
andbnota = Signal(0)
out = Signal(0)
n1 = Not(a,nota)
n2 = Not(b,notb)
n3 = And(a,notb,andanotb)
n4 = And(b,nota,andbnota)
n5 = Or(andanotb,andbnota,out)
@always_comb
def f():
z.next = out
return f, n1, n2, n3, n4, n5
def makeERE(erlist, symbols):
if type(erlist) is list:
negflag = False
orflag = False
catflag = False
andflag = False
#need some initial ERE to make sure this works correctly
currentERE = Empty()
for ind, obj in enumerate(erlist):
if obj == "*":
if ind == 0:
raise SyntaxError("Kleene closure must be after stuff")
currentERE = Kleene.getERE(currentERE)
elif obj == "~":
negflag = True
continue
elif obj == "|":
orflag = True
continue
elif obj == "+":
catflag = True
continue
elif obj == "&":
andflag = True
continue
else:
if ind == 0 | negflag:
currentERE = EREMachine.makeERE(obj, symbols)
elif orflag:
currentERE = Or.getERE(
[currentERE,
EREMachine.makeERE(obj, symbols)])
orflag = False
elif catflag:
currentERE = Concat.getERE(
currentERE, EREMachine.makeERE(obj, symbols))
catflag = False
elif andflag:
currentERE = Negation.getERE(
Concat.getERE(
Negation.getERE(currentERE),
Negation.getERE(
EREMachine.makeERE(obj, symbols))))
andflag = False
else:
currentERE = Concat.getERE(
currentERE, EREMachine.makeERE(obj, symbols))
if negflag:
currentERE = Negation.getERE(currentERE)
negflag = False
return currentERE
else:
if erlist == 'empty':
return Empty.getERE()
elif erlist == 'epsilon':
return Epsilon.getERE()
elif erlist in symbols:
return Symbol.getERE(erlist)
elif not erlist:
return
else:
raise ValueError(
'Either you have used a symbol not tied to event, or epsilon/empty is misspelled'
)