fix pulse threshold selection

tests/test_wave_sim.py

@@ -5,6 +5,38 @@ from kyupy.logic_sim import LogicSim
 from kyupy import logic, bench, sim
 from kyupy.logic import mvarray
 
+def test_xnor2_delays():
+    op = (sim.XNOR2, 2, 0, 1, 3, 3, -1, 0, 0)
+    #op = (0b0111, 4, 0, 1)
+    c = np.full((4*16, 1), TMAX)  # 4 waveforms of capacity 16
+    c_locs = np.zeros((4,), dtype='int')
+    c_caps = np.zeros((4,), dtype='int')
+
+    for i in range(4): c_locs[i], c_caps[i] = i*16, 16  # 1:1 mapping
+    delays = np.zeros((1, 4, 2, 2))
+    delays[0, 0, 0, 0] = 0.031  # A rise -> Z rise
+    delays[0, 0, 0, 1] = 0.027  # A rise -> Z fall
+    delays[0, 0, 1, 0] = 0.033  # A fall -> Z rise
+    delays[0, 0, 1, 1] = 0.037  # A fall -> Z fall
+    delays[0, 1, 0, 0] = 0.032  # B rise -> Z rise
+    delays[0, 1, 0, 1] = 0.030  # B rise -> Z fall
+    delays[0, 1, 1, 0] = 0.038  # B fall -> Z rise
+    delays[0, 1, 1, 1] = 0.036  # B fall -> Z fall
+
+    simctl_int = np.asarray([0], dtype=np.int32)
+
+    def wave_assert(inputs, output):
+        for i, a in zip(inputs, c.reshape(-1,16)): a[:len(i)] = i
+        wave_eval_cpu(op, c, c_locs, c_caps, 0, delays, simctl_int)
+        for i, v in enumerate(output): np.testing.assert_allclose(c.reshape(-1,16)[2,i], v)
+
+    wave_assert([[TMIN,TMAX],[TMIN,TMAX]], [TMIN,TMAX])      # XNOR(1,1) => 1
+    wave_assert([[TMAX,TMAX],[TMIN,TMAX]], [TMAX])           # XNOR(0,1) => 0
+    # using Afall/Zfall for pulse length, bug: was using Arise/Zfall
+    #wave_assert([[0.07, 0.10, TMAX], [0.0, TMAX]], [TMIN, 0.03, 0.101, 0.137, TMAX])
+    wave_assert([[0.07, 0.10, TMAX], [0.0, TMAX]], [TMIN, 0.03, TMAX])
+    wave_assert([[0.06, 0.10, TMAX], [0.0, TMAX]], [TMIN, 0.03, 0.091, 0.137, TMAX])
+
 def test_nand_delays():
     op = (sim.NAND4, 4, 0, 1, 2, 3, -1, 0, 0)
     #op = (0b0111, 4, 0, 1)