uhd: fix get_xx_freq_range to use analog bw/2

The proper equation should be:

max_freq = max_lo + min(adc/2, bw/2) - sr/2

2 files changed, 10 insertions, 2 deletions

diff --git a/host/include/uhd/usrp/multi_usrp.hpp b/host/include/uhd/usrp/multi_usrp.hpp
index 2e83823ba..d60f0e60c 100644
--- a/host/include/uhd/usrp/multi_usrp.hpp
+++ b/host/include/uhd/usrp/multi_usrp.hpp
@@ -441,6 +441,10 @@ public:
 
     /*!
      * Get the RX center frequency range.
+     * This range includes the overall tunable range of the RX chain,
+     * including frontend chain and digital down conversion chain.
+     * This tunable limit does not include the baseband bandwidth;
+     * users should assume that the actual range is +/- samp_rate/2.
      * \param chan the channel index 0 to N-1
      * \return a frequency range object
      */
@@ -694,6 +698,10 @@ public:
 
     /*!
      * Get the TX center frequency range.
+     * This range includes the overall tunable range of the TX chain,
+     * including frontend chain and digital up conversion chain.
+     * This tunable limit does not include the baseband bandwidth;
+     * users should assume that the actual range is +/- samp_rate/2.
      * \param chan the channel index 0 to N-1
      * \return a frequency range object
      */
diff --git a/host/lib/usrp/multi_usrp.cpp b/host/lib/usrp/multi_usrp.cpp
index 0331cf93a..eba3157a9 100644
--- a/host/lib/usrp/multi_usrp.cpp
+++ b/host/lib/usrp/multi_usrp.cpp
@@ -81,8 +81,8 @@ static meta_range_t make_overall_tune_range(
     meta_range_t range;
     BOOST_FOREACH(const range_t &sub_range, fe_range){
         range.push_back(range_t(
-            sub_range.start() + std::max(dsp_range.start(), -bw),
-            sub_range.stop() + std::min(dsp_range.stop(), bw),
+            sub_range.start() + std::max(dsp_range.start(), -bw/2),
+            sub_range.stop() + std::min(dsp_range.stop(), bw/2),
             dsp_range.step()
         ));
     }