bist.py 文件源码

def __init__(self, n_out, n_state=31, taps=[27, 30]):
        self.o = Signal(n_out)

        # # #

        state = Signal(n_state)
        curval = [state[i] for i in range(n_state)]
        curval += [0]*(n_out - n_state)
        for i in range(n_out):
            nv = ~reduce(xor, [curval[tap] for tap in taps])
            curval.insert(0, nv)
            curval.pop()

        self.sync += [
            state.eq(Cat(*curval[:n_state])),
            self.o.eq(Cat(*curval))
        ]