from scipy import signal from math import cos, pi from migen.fhdl.structure import * from migen.fhdl import verilog from migen.corelogic.misc import optree from migen.fhdl import autofragment from migen.sim.generic import Simulator from migen.sim.icarus import Runner class FIR: def __init__(self, coef, wsize=16): self.coef = coef self.wsize = wsize self.i = Signal(BV(self.wsize, True)) self.o = Signal(BV(self.wsize, True)) def get_fragment(self): muls = [] sync = [] src = self.i for c in self.coef: sreg = Signal(BV(self.wsize, True)) sync.append(sreg.eq(src)) src = sreg c_fp = int(c*2**(self.wsize - 1)) c_e = Constant(c_fp, BV(bits_for(c_fp), True)) muls.append(c_e*sreg) sum_full = Signal(BV(2*self.wsize-1, True)) sync.append(sum_full.eq(optree("+", muls))) comb = [self.o.eq(sum_full[self.wsize-1:])] return Fragment(comb, sync) class TB: def __init__(self, fir, frequency): self.fir = fir self.frequency = frequency self.inputs = [] self.outputs = [] def do_simulation(self, s): f = 2**(self.fir.wsize - 1) v = 0.1*cos(2*pi*self.frequency*s.cycle_counter) s.wr(self.fir.i, int(f*v)) self.inputs.append(v) self.outputs.append(s.rd(self.fir.o)/f) def get_fragment(self): return Fragment(sim=[self.do_simulation]) def main(): coef = signal.remez(80, [0, 0.1, 0.1, 0.5], [1, 0]) fir = FIR(coef) tb = TB(fir, 0.3) fragment = autofragment.from_local() sim = Simulator(fragment, Runner()) sim.run(200) print(tb.inputs) print(tb.outputs) main()