diff --git a/litex/gen/genlib/__init__.py b/litex/gen/genlib/__init__.py new file mode 100644 index 000000000..e69de29bb diff --git a/litex/gen/genlib/misc.py b/litex/gen/genlib/misc.py new file mode 100644 index 000000000..a44ef6d39 --- /dev/null +++ b/litex/gen/genlib/misc.py @@ -0,0 +1,104 @@ +from migen.fhdl.structure import * +from migen.fhdl.module import Module +from migen.fhdl.bitcontainer import bits_for + + +def split(v, *counts): + r = [] + offset = 0 + for n in counts: + if n != 0: + r.append(v[offset:offset+n]) + else: + r.append(None) + offset += n + return tuple(r) + + +def displacer(signal, shift, output, n=None, reverse=False): + if shift is None: + return output.eq(signal) + if n is None: + n = 2**len(shift) + w = len(signal) + 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 shift is None: + return output.eq(signal) + if n is None: + n = 2**len(shift) + w = len(output) + cases = {} + for i in range(n): + if reverse: + s = n - i - 1 + else: + s = i + cases[i] = [output.eq(signal[s*w:(s+1)*w])] + return Case(shift, cases).makedefault() + + +def timeline(trigger, events): + lastevent = max([e[0] for e in events]) + counter = Signal(max=lastevent+1) + + counterlogic = If(counter != 0, + counter.eq(counter + 1) + ).Elif(trigger, + counter.eq(1) + ) + # insert counter reset if it doesn't naturally overflow + # (test if lastevent+1 is a power of 2) + if (lastevent & (lastevent + 1)) != 0: + counterlogic = If(counter == lastevent, + counter.eq(0) + ).Else( + counterlogic + ) + + def get_cond(e): + if e[0] == 0: + return trigger & (counter == 0) + else: + return counter == e[0] + sync = [If(get_cond(e), *e[1]) for e in events] + sync.append(counterlogic) + return sync + + +class WaitTimer(Module): + def __init__(self, t): + self.wait = Signal() + self.done = Signal() + + # # # + + count = Signal(bits_for(t), reset=t) + self.comb += self.done.eq(count == 0) + self.sync += \ + If(self.wait, + If(~self.done, count.eq(count - 1)) + ).Else(count.eq(count.reset)) + + +class BitSlip(Module): + def __init__(self, dw): + self.i = Signal(dw) + self.o = Signal(dw) + self.value = Signal(max=dw) + + # # # + + r = Signal(2*dw) + self.sync += r.eq(Cat(r[dw:], self.i)) + cases = {} + for i in range(dw): + cases[i] = self.o.eq(r[i:dw+i]) + self.sync += Case(self.value, cases)