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