from migen.fhdl.structure import * from migen.fhdl.structure import _Operator def multimux(sel, inputs, output): n = len(inputs) i = 0 statements = [] for osig in output: choices = [x[i] for x in inputs] cases = [[Constant(j, sel.bv), osig.eq(choices[j])] for j in range(n)] cases[n-1][0] = Default() statements.append(Case(sel, *cases)) i += 1 return statements def optree(op, operands, lb=None, ub=None, default=None): if lb is None: lb = 0 if ub is None: ub = len(operands) l = ub - lb if l == 0: if default is None: raise AttributeError else: return default elif l == 1: return operands[lb] else: s = lb + l//2 return _Operator(op, [optree(op, operands, lb, s, default), optree(op, operands, s, ub, default)]) def split(v, *counts): r = [] offset = 0 for n in counts: r.append(v[offset:offset+n]) offset += n return tuple(r) def displacer(signal, shift, output, n=None, reverse=False): if n is None: n = 2**shift.bv.width w = signal.bv.width if reverse: r = reversed(range(n)) else: r = range(n) l = [Replicate(shift == i, w) & signal for i in r] return output.eq(Cat(*l)) def chooser(signal, shift, output, n=None, reverse=False): if n is None: n = 2**shift.bv.width w = output.bv.width cases = [] for i in range(n): if reverse: s = n - i - 1 else: s = i cases.append([Constant(i, shift.bv), output.eq(signal[s*w:(s+1)*w])]) cases[n-1][0] = Default() return Case(shift, *cases)