PRBS: a Pseudo-random binary sequence (PRBS) generator class.

Implemeted with a Galois LFSR for speed and flexibility compared to Fibonacci version.

Aliases for three popular PRBS' are added for convenience - PRBS9, PRBS15 and PRBS64.

Note that we can't test PRBS64 completely, because the sequence is too long to
be generated.

Change-Id: Ib5331ba5d0b5819929541686fdd87905e2177b74
diff --git a/CommonLibs/PRBSTest.cpp b/CommonLibs/PRBSTest.cpp
new file mode 100644
index 0000000..b83e93d
--- /dev/null
+++ b/CommonLibs/PRBSTest.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2017 Alexander Chemeris <Alexander.Chemeris@fairwaves.co>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "PRBS.h"
+#include <iostream>
+#include <cstdlib>
+#include <assert.h>
+
+void testPrbs(PRBS &prbs, uint64_t expectedPeriod)
+{
+  uint64_t period = 0;
+  do {
+    std::cout << prbs.generateBit();
+    period++;
+  } while (!prbs.isFinished());
+  std::cout << std::endl;
+  std::cout << "Period: " << period << std::endl;
+  assert(period == expectedPeriod);
+}
+
+int main(int argc, char *argv[])
+{
+  PRBS9 prbs9(0x01);
+  testPrbs(prbs9, (1<<9)-1);
+  PRBS15 prbs15(0x01);
+  testPrbs(prbs15, (1<<15)-1);
+}