Add symbol coding namespace, NRZI decoder.

firmware/baseband/symbol_coding.hpp

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __SYMBOL_CODING_H__
+#define __SYMBOL_CODING_H__
+
+#include <cstdint>
+
+namespace symbol_coding {
+
+class NRZIDecoder {
+public:
+	uint_fast8_t operator()(const uint_fast8_t symbol) {
+		const auto out = (~(symbol ^ last)) & 1;
+		last = symbol;
+		return out;
+	}
+
+private:
+	uint_fast8_t last { 0 };
+};
+
+} /* namespace symbol_coding */
+
+#endif/*__SYMBOL_CODING_H__*/