cores: Corrected scaling_adjustment calculation

Compensate for headroom required to rotate a signal in
the CORDIC. Fixes some CORDIC-related clipping issues,
that reduced ENOB to 15 or 14.5 bits.

2 files changed, 10 insertions, 0 deletions

diff --git a/host/lib/usrp/x300/x300_impl.cpp b/host/lib/usrp/x300/x300_impl.cpp
index f57556a8b..1e424414e 100644
--- a/host/lib/usrp/x300/x300_impl.cpp
+++ b/host/lib/usrp/x300/x300_impl.cpp
@@ -1334,6 +1334,14 @@ void x300_impl::register_loopback_self_test(wb_iface::sptr iface)
     UHD_MSG(status) << ((test_fail)? " fail" : "pass") << std::endl;
 }
 
+void x300_impl::radio_loopback(wb_iface::sptr iface, const bool on)
+{
+  iface->poke32(radio::sr_addr(radio::LOOPBACK), (on ? 0x1 : 0x0));
+  UHD_MSG(status) << ((on)? "Radio Loopback On" : "Radio Loopback Off") << std::endl;
+}
+
+
+
 /***********************************************************************
  * clock and time control logic
  **********************************************************************/
diff --git a/host/lib/usrp/x300/x300_impl.hpp b/host/lib/usrp/x300/x300_impl.hpp
index 78c497ad9..1630047af 100644
--- a/host/lib/usrp/x300/x300_impl.hpp
+++ b/host/lib/usrp/x300/x300_impl.hpp
@@ -250,6 +250,8 @@ private:
 
     void register_loopback_self_test(uhd::wb_iface::sptr iface);
 
+    void radio_loopback(uhd::wb_iface::sptr iface, const bool on);
+
      /*! \brief Initialize the radio component on a given slot.
       *
       * Call this function once per slot (A and B) and motherboard to initialize all the radio components.