1 files changed, 70 insertions, 0 deletions
diff --git a/host/include/uhd/rfnoc/null_block_ctrl.hpp b/host/include/uhd/rfnoc/null_block_ctrl.hpp
new file mode 100644
index 000000000..8a982b3e0
--- /dev/null
+++ b/host/include/uhd/rfnoc/null_block_ctrl.hpp
@@ -0,0 +1,70 @@
+//
+// Copyright 2014-2018 Ettus Research, a National Instruments Company
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#ifndef INCLUDED_LIBUHD_RFNOC_NULL_BLOCK_CTRL_HPP
+#define INCLUDED_LIBUHD_RFNOC_NULL_BLOCK_CTRL_HPP
+
+#include <uhd/rfnoc/source_block_ctrl_base.hpp>
+#include <uhd/rfnoc/sink_block_ctrl_base.hpp>
+
+namespace uhd {
+    namespace rfnoc {
+
+/*! \brief Provide access to a 'null block'.
+ *
+ * A 'null block' is a specific block, which comes with a couple
+ * of features useful for testing:
+ * - It can produce data at a given line rate, with a configurable
+ *   packet size.
+ * - It can be used to dump packets ("null sink", "bit bucket")
+ *
+ * This block also serves as an example of how to create your own
+ * C++ classes to control your block.
+ *
+ * As a true source, it understands the following stream commands:
+ * - STREAM_MODE_START_CONTINUOUS
+ * - STREAM_MODE_STOP_CONTINUOUS
+ *
+ * Other stream commands are not understood and issue_stream_cmd()
+ * will throw if it receives them.
+ */
+class null_block_ctrl : public source_block_ctrl_base, public sink_block_ctrl_base
+{
+public:
+    // This macro must always be at the top of the public section in an RFNoC block class
+    UHD_RFNOC_BLOCK_OBJECT(null_block_ctrl)
+
+    //! Set this register to number of lines per packet
+    static const uint32_t SR_LINES_PER_PACKET = 129;
+    //! Set this register to number of cycles between producing a line
+    static const uint32_t SR_LINE_RATE = 130;
+    //! Set this register to non-zero to start producing data
+    static const uint32_t SR_ENABLE_STREAM = 131;
+
+    static const size_t DEFAULT_LINES_PER_PACKET = 32;
+    static const size_t BYTES_PER_LINE = 8;
+
+    //! Custom function to set the rate at which data is produced.
+    // Note: This is 'cycles per line', so the bit rate is actually
+    // 64 times this value (byte/s is 8*rate etc.)
+    //
+    // Equivalent to writing to line_rate/value in the property tree.
+    //
+    // \param The rate you want to set this to
+    // \param The clock rate of this block's clock domain
+    // \returns the actual line rate (will find closest possible).
+    virtual double set_line_rate(double rate, double clock_rate=166.6e6) = 0;
+
+    //! Return the current line rate. Equivalent to reading line_rate/value
+    // from the property tree.
+    virtual double get_line_rate(double clock_rate=166.6e6) const = 0;
+
+}; /* class null_block_ctrl*/
+
+}} /* namespace uhd::rfnoc */
+
+#endif /* INCLUDED_LIBUHD_RFNOC_NULL_BLOCK_CTRL_HPP */
+// vim: sw=4 et: