nmigen/test/compat/test_fsm.py

   1 import unittest
   2 from itertools import count
   3
   4 from ...compat import *
   5 from ...compat.genlib.fsm import FSM
   6
   7 from .support import SimCase
   8
   9
  10 class FSMCase(SimCase, unittest.TestCase):
  11     class TestBench(Module):
  12         def __init__(self):
  13             self.ctrl   = Signal()
  14             self.data   = Signal()
  15             self.status = Signal(8)
  16
  17             self.submodules.dut = FSM()
  18             self.dut.act("IDLE",
  19                 If(self.ctrl,
  20                     NextState("START")
  21                 )
  22             )
  23             self.dut.act("START",
  24                 If(self.data,
  25                     NextState("SET-STATUS-LOW")
  26                 ).Else(
  27                     NextState("SET-STATUS")
  28                 )
  29             )
  30             self.dut.act("SET-STATUS",
  31                 NextValue(self.status, 0xaa),
  32                 NextState("IDLE")
  33             )
  34             self.dut.act("SET-STATUS-LOW",
  35                 NextValue(self.status[:4], 0xb),
  36                 NextState("IDLE")
  37             )
  38
  39     def assertState(self, fsm, state):
  40         self.assertEqual(fsm.decoding[(yield fsm.state)], state)
  41
  42     def test_next_state(self):
  43         def gen():
  44             yield from self.assertState(self.tb.dut, "IDLE")
  45             yield
  46             yield from self.assertState(self.tb.dut, "IDLE")
  47             yield self.tb.ctrl.eq(1)
  48             yield
  49             yield from self.assertState(self.tb.dut, "IDLE")
  50             yield self.tb.ctrl.eq(0)
  51             yield
  52             yield from self.assertState(self.tb.dut, "START")
  53             yield
  54             yield from self.assertState(self.tb.dut, "SET-STATUS")
  55             yield self.tb.ctrl.eq(1)
  56             yield
  57             yield from self.assertState(self.tb.dut, "IDLE")
  58             yield self.tb.ctrl.eq(0)
  59             yield self.tb.data.eq(1)
  60             yield
  61             yield from self.assertState(self.tb.dut, "START")
  62             yield self.tb.data.eq(0)
  63             yield
  64             yield from self.assertState(self.tb.dut, "SET-STATUS-LOW")
  65         self.run_with(gen())
  66
  67     def test_next_value(self):
  68         def gen():
  69             self.assertEqual((yield self.tb.status), 0x00)
  70             yield self.tb.ctrl.eq(1)
  71             yield
  72             yield self.tb.ctrl.eq(0)
  73             yield
  74             yield
  75             yield from self.assertState(self.tb.dut, "SET-STATUS")
  76             yield self.tb.ctrl.eq(1)
  77             yield
  78             self.assertEqual((yield self.tb.status), 0xaa)
  79             yield self.tb.ctrl.eq(0)
  80             yield self.tb.data.eq(1)
  81             yield
  82             yield self.tb.data.eq(0)
  83             yield
  84             yield from self.assertState(self.tb.dut, "SET-STATUS-LOW")
  85             yield
  86             self.assertEqual((yield self.tb.status), 0xab)
  87         self.run_with(gen())