82 lines
1.9 KiB
Python
82 lines
1.9 KiB
Python
from migen.fhdl.structure import *
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from migen.fhdl.structure import _Operator
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def optree(op, operands, lb=None, ub=None, default=None):
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if lb is None:
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lb = 0
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if ub is None:
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ub = len(operands)
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l = ub - lb
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if l == 0:
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if default is None:
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raise AttributeError
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else:
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return default
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elif l == 1:
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return operands[lb]
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else:
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s = lb + l//2
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return _Operator(op,
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[optree(op, operands, lb, s, default),
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optree(op, operands, s, ub, default)])
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def split(v, *counts):
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r = []
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offset = 0
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for n in counts:
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r.append(v[offset:offset+n])
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offset += n
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return tuple(r)
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def displacer(signal, shift, output, n=None, reverse=False):
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if n is None:
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n = 2**len(shift)
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w = len(signal)
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if reverse:
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r = reversed(range(n))
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else:
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r = range(n)
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l = [Replicate(shift == i, w) & signal for i in r]
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return output.eq(Cat(*l))
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def chooser(signal, shift, output, n=None, reverse=False):
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if n is None:
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n = 2**len(shift)
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w = len(output)
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cases = []
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for i in range(n):
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if reverse:
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s = n - i - 1
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else:
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s = i
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cases.append([Constant(i, shift.bv), output.eq(signal[s*w:(s+1)*w])])
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cases[n-1][0] = Default()
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return Case(shift, *cases)
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def timeline(trigger, events):
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lastevent = max([e[0] for e in events])
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counter = Signal(BV(bits_for(lastevent)))
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counterlogic = If(counter != Constant(0, counter.bv),
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counter.eq(counter + Constant(1, counter.bv))
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).Elif(trigger,
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counter.eq(Constant(1, counter.bv))
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)
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# insert counter reset if it doesn't naturally overflow
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# (test if lastevent+1 is a power of 2)
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if (lastevent & (lastevent + 1)) != 0:
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counterlogic = If(counter == lastevent,
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counter.eq(Constant(0, counter.bv))
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).Else(
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counterlogic
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)
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def get_cond(e):
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if e[0] == 0:
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return trigger & (counter == Constant(0, counter.bv))
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else:
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return counter == Constant(e[0], counter.bv)
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sync = [If(get_cond(e), *e[1]) for e in events]
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sync.append(counterlogic)
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return sync
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