minor changes; preset changes; rotate output

tools/lfsrcalc.py

@@ -0,0 +1,28 @@
+#!/usr/bin/python
+
+print "Period,nbits,feedback,mask"
+
+for n in range(1,18):
+    mask = (1<<n)-1
+    hibit = (1<<(n-1))
+    for i in range(0,1<<n):
+        for invert in [0,1]:
+            x = 1
+            seq = []
+            seen = set()
+            while x and not x in seen:
+                seq.append(x)
+                seen.add(x)
+                feedback = x & hibit
+                x = ((x << 1) & mask)
+                if invert:
+                    if not feedback:
+                        x ^= i
+                else:
+                    if feedback:
+                        x ^= i
+            if x:
+                seqindex = seq.index(x)
+                seqlen = len(seq) - seqindex
+                if seqlen>1:
+                    print seqlen, "#(%d,%d'%s,%d)" % (n,n,bin(i)[1:],invert), seqindex