def convert(hdl, width=8):
B = Signal(intbv(0)[width:])
G = Signal(intbv(0)[width:])
inst = bin2gray(B, G)
inst.convert(hdl=hdl)
def convert(hdl, width=8):
B = Signal(intbv(0)[width:])
G = Signal(intbv(0)[width:])
inst = bin2gray(B, G)
inst.convert(hdl=hdl)
def gray_inc(graycnt, enable, clock, reset, width):
bincnt = Signal(modbv(0)[width:])
inc_0 = inc(bincnt, enable, clock, reset)
bin2gray_0 = bin2gray(B=bincnt, G=graycnt)
return inc_0, bin2gray_0
def runTests(self, test):
"""Helper method to run the actual tests."""
for w in range(1, MAX_WIDTH):
B = Signal(intbv(0)[w:])
G = Signal(intbv(0)[w:])
dut = bin2gray(B, G)
check = test(B, G)
sim = Simulation(dut, check)
sim.run(quiet=1)
def runTests(self, test):
"""Helper method to run the actual tests."""
for w in range(1, MAX_WIDTH):
B = Signal(intbv(0)[w:])
G = Signal(intbv(0)[w:])
dut = bin2gray(B, G)
check = test(B, G)
sim = Simulation(dut, check)
sim.run(quiet=1)
def testbench(width):
B = Signal(intbv(0)[width:])
G = Signal(intbv(0)[width:])
dut = bin2gray(B, G)
dut.config_sim(trace=True)
@instance
def stimulus():
for i in range(2**width):
B.next = intbv(i)
yield delay(10)
print("B: " + bin(B, width) + "| G: " + bin(G, width))
return dut, stimulus
def testbench(width):
B = Signal(intbv(0)[width:])
G = Signal(intbv(0)[width:])
dut = bin2gray(B, G)
dut.config_sim(trace=True)
@instance
def stimulus():
for i in range(2**width):
B.next = intbv(i)
yield delay(10)
print("B: " + bin(B, width) + "| G: " + bin(G, width))
return dut, stimulus
def testUniqueCodeWords(self):
""" Check that all codewords occur exactly once """
def test(B, G, width):
actual = []
for i in range(2**width):
B.next = intbv(i)
yield delay(10)
actual.append(int(G))
actual.sort()
expected = list(range(2**width))
self.assertEqual(actual, expected)
for width in range(1, MAX_WIDTH):
B = Signal(intbv(1))
G = Signal(intbv(0))
dut = bin2gray(B, G, width)
check = test(B, G, width)
sim = Simulation(dut, check)
sim.run(quiet=1)
def testSingleBitChange(self):
""" Check that only one bit changes in successive codewords """
def test(B, G, G_Z, width):
B.next = intbv(0)
yield delay(10)
for i in range(1, 2**width):
G_Z.next = G
B.next = intbv(i)
yield delay(10)
diffcode = bin(G ^ G_Z)
self.assertEqual(diffcode.count('1'), 1)
for width in range(2, MAX_WIDTH):
B = Signal(intbv(1))
G = Signal(intbv(0))
G_Z = Signal(intbv(0))
dut = bin2gray(B, G, width)
check = test(B, G, G_Z, width)
sim = Simulation(dut, check)
sim.run(quiet=1)
def testUniqueCodeWords(self):
""" Check that all codewords occur exactly once """
def test(B, G, width):
actual = []
for i in range(2**width):
B.next = intbv(i)
yield delay(10)
actual.append(int(G))
actual.sort()
expected = range(2**width)
self.assertEqual(actual, expected)
for width in range(1, MAX_WIDTH):
B = Signal(intbv(-1))
G = Signal(intbv(0))
dut = bin2gray(B, G, width)
check = test(B, G, width)
sim = Simulation(dut, check)
sim.run(quiet=1)
def testOriginalGrayCode(self):
"""Check that the code is an original Gray code."""
Rn = []
def stimulus(B, G, n):
for i in range(2**n):
B.next = intbv(i)
yield delay(10)
Rn.append(bin(G, width=n))
Ln = ['0', '1'] # n == 1
for w in range(2, MAX_WIDTH):
Ln = nextLn(Ln)
del Rn[:]
B = Signal(intbv(0)[w:])
G = Signal(intbv(0)[w:])
dut = bin2gray(B, G)
stim = stimulus(B, G, w)
sim = Simulation(dut, stim)
sim.run(quiet=1)
self.assertEqual(Ln, Rn)
def testSingleBitChange(self):
""" Check that only one bit changes in successive codewords """
def test(B, G, width):
B.next = intbv(0)
yield delay(10)
for i in range(1, 2**width):
G_Z.next = G
B.next = intbv(i)
yield delay(10)
diffcode = bin(G ^ G_Z)
self.assertEqual(diffcode.count('1'), 1)
for width in range(1, MAX_WIDTH):
B = Signal(intbv(-1))
G = Signal(intbv(0))
G_Z = Signal(intbv(0))
dut = bin2gray(B, G, width)
check = test(B, G, width)
sim = Simulation(dut, check)
sim.run(quiet=1)
