30 lines
858 B
Python
30 lines
858 B
Python
from migen.fhdl.structure import *
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class FSM:
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def __init__(self, *states):
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self._state_bv = BV(bits_for(len(states)-1))
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self._state = Signal(self._state_bv)
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self._next_state = Signal(self._state_bv)
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for state, n in zip(states, range(len(states))):
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setattr(self, state, Constant(n, self._state_bv))
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self.actions = [[] for i in range(len(states))]
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def reset_state(self, state):
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self._state.reset = state
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def next_state(self, state):
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return self._next_state.eq(state)
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def act(self, state, *statements):
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self.actions[state.n] += statements
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def get_fragment(self):
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cases = [[Constant(s, self._state_bv)] + a
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for s, a in zip(range(len(self.actions)), self.actions) if a]
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comb = [
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self._next_state.eq(self._state),
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Case(self._state, *cases)
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]
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sync = [self._state.eq(self._next_state)]
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return Fragment(comb, sync)
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