gen/genlib/misc: add BitSlip

litex/gen/genlib/misc.py

@@ -86,3 +86,19 @@ class WaitTimer(Module):
             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)