3 files changed, 47 insertions, 1 deletions

diff --git a/host/lib/usrp/mboard_eeprom.cpp b/host/lib/usrp/mboard_eeprom.cpp
index 869a38478..03096691e 100644
--- a/host/lib/usrp/mboard_eeprom.cpp
+++ b/host/lib/usrp/mboard_eeprom.cpp
@@ -223,6 +223,7 @@ struct e100_eeprom_map{
     unsigned char env_setting[64];
     unsigned char serial[10];
     unsigned char name[NAME_MAX_LEN];
+    float master_clock_rate;
 };
 
 template <typename T> static const byte_vector_t to_bytes(const T &item){
@@ -254,6 +255,19 @@ static void load_e100(mboard_eeprom_t &mb_eeprom, i2c_iface &iface){
     load_e100_string_xx(env_setting);
     load_e100_string_xx(serial);
     load_e100_string_xx(name);
+
+    //extract the master clock rate
+    float master_clock_rate = 0;
+    const byte_vector_t rate_bytes = iface.read_eeprom(
+        E100_EEPROM_ADDR, offsetof(e100_eeprom_map, master_clock_rate), sizeof(master_clock_rate)
+    );
+    std::copy(
+        rate_bytes.begin(), rate_bytes.end(), //source
+        reinterpret_cast<boost::uint8_t *>(&master_clock_rate) //destination
+    );
+    if (master_clock_rate > 1e6 and master_clock_rate < 1e9){
+        mb_eeprom["master_clock_rate"] = boost::lexical_cast<std::string>(master_clock_rate);
+    }
 }
 
 static void store_e100(const mboard_eeprom_t &mb_eeprom, i2c_iface &iface){
@@ -289,6 +303,17 @@ static void store_e100(const mboard_eeprom_t &mb_eeprom, i2c_iface &iface){
     store_e100_string_xx(serial);
     store_e100_string_xx(name);
 
+    //store the master clock rate
+    if (mb_eeprom.has_key("master_clock_rate")){
+        const float master_clock_rate = float(boost::lexical_cast<double>(mb_eeprom["master_clock_rate"]));
+        const byte_vector_t rate_bytes(
+            reinterpret_cast<const boost::uint8_t *>(&master_clock_rate),
+            reinterpret_cast<const boost::uint8_t *>(&master_clock_rate) + sizeof(master_clock_rate)
+        );
+        iface.write_eeprom(
+            E100_EEPROM_ADDR, offsetof(e100_eeprom_map, master_clock_rate), rate_bytes
+        );
+    }
 }
 
 /***********************************************************************
diff --git a/host/lib/usrp/usrp_e100/clock_ctrl.cpp b/host/lib/usrp/usrp_e100/clock_ctrl.cpp
index 1ac2b804c..851ce29b0 100644
--- a/host/lib/usrp/usrp_e100/clock_ctrl.cpp
+++ b/host/lib/usrp/usrp_e100/clock_ctrl.cpp
@@ -184,7 +184,24 @@ public:
 
         this->use_internal_ref();
 
-        this->set_fpga_clock_rate(DEFAULT_OUTPUT_RATE); //initialize to something
+        //initialize the FPGA clock to something
+        bool fpga_clock_initialized = false;
+        try{
+            if (_iface->mb_eeprom.has_key("master_clock_rate")){
+                std::cout << "Read FPGA clock rate from EEPROM setting." << std::endl;
+                const double master_clock_rate = boost::lexical_cast<double>(_iface->mb_eeprom["master_clock_rate"]);
+                std::cout << boost::format("Initializing FPGA clock to %fMHz...") % (master_clock_rate/1e6) << std::endl;
+                this->set_fpga_clock_rate(master_clock_rate);
+                fpga_clock_initialized = true;
+            }
+        }
+        catch(const std::exception &e){
+            std::cerr << "Error setting FPGA clock rate from EEPROM: " << e.what() << std::endl;
+        }
+        if (not fpga_clock_initialized){ //was not set... use the default rate
+            std::cout << boost::format("Initializing FPGA clock to %fMHz...") % (DEFAULT_OUTPUT_RATE/1e6) << std::endl;
+            this->set_fpga_clock_rate(DEFAULT_OUTPUT_RATE);
+        }
 
         this->enable_test_clock(ENABLE_THE_TEST_OUT);
         this->enable_rx_dboard_clock(false);
diff --git a/host/lib/usrp/usrp_e100/mboard_impl.cpp b/host/lib/usrp/usrp_e100/mboard_impl.cpp
index 29e3c5da2..5f4a208d3 100644
--- a/host/lib/usrp/usrp_e100/mboard_impl.cpp
+++ b/host/lib/usrp/usrp_e100/mboard_impl.cpp
@@ -207,6 +207,10 @@ void usrp_e100_impl::mboard_set(const wax::obj &key, const wax::obj &val){
         return;
 
     case MBOARD_PROP_CLOCK_RATE:
+        std::cerr << "Helpful message:" << std::endl;
+        std::cerr << "    I see that you are setting the master clock rate from the API." << std::endl;
+        std::cerr << "    You may find it more convenient to burn this setting into the EEPROM." << std::endl;
+        std::cerr << "    See the application notes for USRP-E1XX for further instructions." << std::endl;
         _clock_ctrl->set_fpga_clock_rate(val.as<double>());
         return;