Updated documentation and improved XCVR RSSI calculation

    Documented dboard sensors
    Documented DBSRX2
    Added description of direct conversion vs low IF for each dboard
    Added E1xx docs for adding refclock and pps connectors

    XCVR rssi calculation was in unscaled dB units
        Used chart in datasheet (pg 16) to rescale to dBm

3 files changed, 144 insertions, 26 deletions

diff --git a/host/docs/dboards.rst b/host/docs/dboards.rst
index 419456df2..373189441 100644
--- a/host/docs/dboards.rst
+++ b/host/docs/dboards.rst
@@ -27,12 +27,14 @@ Though the magic of aliasing, you can down-convert signals
 greater than the Nyquist rate of the ADC.
 
 BasicRX Bandwidth (Hz): 
-    For Real-Mode (A or B subdevice): 250M
-    For Complex (AB or BA subdevice): 500M
+
+* For Real-Mode (A or B subdevice): 250M
+* For Complex (AB or BA subdevice): 500M
 
 LFRX Bandwidth (Hz):
-    For Real-Mode (A or B subdevice): 33M
-    For Complex (AB or BA subdevice): 66M
+
+* For Real-Mode (A or B subdevice): 33M
+* For Complex (AB or BA subdevice): 66M
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Basic TX and and LFTX
@@ -49,31 +51,67 @@ Though the magic of aliasing, you can up-convert signals
 greater than the Nyquist rate of the DAC.
 
 BasicTX Bandwidth (Hz): 250M
-    For Real-Mode (A or B subdevice): 250M
-    For Complex (AB or BA subdevice): 500M
+
+* For Real-Mode (A or B subdevice): 250M
+* For Complex (AB or BA subdevice): 500M
 
 LFTX Bandwidth (Hz): 33M
-    For Real-Mode (A or B subdevice): 33M
-    For Complex (AB or BA subdevice): 66M
+
+* For Real-Mode (A or B subdevice): 33M
+* For Complex (AB or BA subdevice): 66M
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 DBSRX
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-The DBSRX board has 1 quadrature subdevice.
+The DBSRX board has 1 quadrature subdevice.  
+It defaults to direct conversion, but can use a low IF through lo_offset in uhd::tune_request_t
 
 Receive Antennas: **J3**
 
 The board has no user selectable antenna setting
 
-Receive Gains: 
-    **GC1**, Range: 0-56dB
-    **GC2**, Range: 0-24dB
+Receive Gains:
+
+* **GC1**, Range: 0-56dB
+* **GC2**, Range: 0-24dB
 
 Bandwidth (Hz): 8M-66M
 
+Sensors:
+
+* **lo_locked**: boolean for LO lock state
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+DBSRX2
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The DBSRX2 board has 1 quadrature subdevice.
+It defaults to direct conversion, but can use a low IF through lo_offset in uhd::tune_request_t
+
+Receive Antennas: **J3**
+
+The board has no user selectable antenna setting
+
+Receive Gains:
+
+* **GC1**, Range: 0-73dB
+* **BBG**, Range: 0-15dB
+
+Bandwidth (Hz): 8M-80M
+
+Sensors:
+
+* **lo_locked**: boolean for LO lock state
+
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 RFX Series
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The RFX Series boards have 2 quadrature subdevices, one transmit, one receive.
+Transmit defaults to low IF and Receive defaults to direct conversion.
+The IF can be adjusted through lo_offset in uhd::tune_request_t
+
+The RFX Series boards have independent receive and transmit LO's and synthesizers 
+allowing full-duplex operation on different transmit and receive frequencies.
+
 Transmit Antennas: **TX/RX**
 
 Receive Antennas: **TX/RX** or **RX2**
@@ -85,12 +123,21 @@ the receive antenna will always be set to RX2, regardless of the settings.
 Receive Gains: **PGA0**, Range: 0-70dB (except RFX400 range is 0-45dB)
 
 Bandwidths (Hz):
- * **RX**: 40M
- * **TX**: 40M
+
+* **RX**: 40M
+* **TX**: 40M
+
+Sensors:
+
+* **lo_locked**: boolean for LO lock state
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 XCVR 2450
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The XCVR2450 has 2 quadrature subdevices, one transmit, one receive.
+Transmit and Receive default to direct conversion but
+can be used in low IF mode through lo_offset in uhd::tune_request_t
+
 The XCVR2450 has a non-contiguous tuning range consisting of a 
 high band (4.9-6.0GHz) and a low band (2.4-2.5GHz).
 
@@ -106,20 +153,35 @@ The XCVR2450 does not support full-duplex mode, attempting to operate
 in full-duplex will result in transmit-only operation.
 
 Transmit Gains:
- * **VGA**, Range: 0-30dB
- * **BB**, Range: 0-5dB
+
+* **VGA**, Range: 0-30dB
+* **BB**, Range: 0-5dB
 
 Receive Gains:
- * **LNA**, Range: 0-30.5dB
- * **VGA**, Range: 0-62dB
+
+* **LNA**, Range: 0-30.5dB
+* **VGA**, Range: 0-62dB
 
 Bandwidths (Hz):
- * **RX**: 15M, 19M, 28M, 36M; (each +-0, 5, or 10%)
- * **TX**: 24M, 36M, 48M
+
+* **RX**: 15M, 19M, 28M, 36M; (each +-0, 5, or 10%)
+* **TX**: 24M, 36M, 48M
+
+Sensors:
+
+* **lo_locked**: boolean for LO lock state
+* **rssi**:      float for rssi in dBm
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 WBX Series
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The WBX Series boards have 2 quadrature subdevices, one transmit, one receive.
+Transmit and Receive default to direct conversion but
+can be used in low IF mode through lo_offset in uhd::tune_request_t
+
+The WBX Series boards have independent receive and transmit LO's and synthesizers 
+allowing full-duplex operation on different transmit and receive frequencies.
+
 Transmit Antennas: **TX/RX**
 
 Receive Antennas: **TX/RX** or **RX2**
@@ -133,17 +195,26 @@ Transmit Gains: **PGA0**, Range: 0-25dB
 Receive Gains: **PGA0**, Range: 0-31.5dB
 
 Bandwidths (Hz):
- * **RX**: 40M
- * **TX**: 40M
+
+* **RX**: 40M
+* **TX**: 40M
+
+Sensors:
+
+* **lo_locked**: boolean for LO lock state
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 TVRX
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The TVRX board has 1 real-mode subdevice.
+It is operated at a low IF.
+
 Receive Antennas: RX
 
 Receive Gains:
- * **RF**, Range: -13.3-50.3dB (frequency-dependent)
- * **IF**, Range: -1.5-32.5dB
+
+* **RF**, Range: -13.3-50.3dB (frequency-dependent)
+* **IF**, Range: -1.5-32.5dB
 
 Bandwidth: 6MHz
 
diff --git a/host/docs/usrp_e1xx.rst b/host/docs/usrp_e1xx.rst
index fb5848bad..2818a0a65 100644
--- a/host/docs/usrp_e1xx.rst
+++ b/host/docs/usrp_e1xx.rst
@@ -63,3 +63,41 @@ Run the following commands to restore the clock generator to a usable state:
 
     cd <install-path>/share/uhd/usrp_e_utilities
     ./usrp-e-utility --fpga=../images/usrp_e100_pt_fpga.bin --reclk
+
+
+------------------------------------------------------------------------
+Clock Synchronization
+------------------------------------------------------------------------
+
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Ref Clock - 10MHz
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The E1xx has a 10MHz TCXO which can be used to discipline the flexible clocking by 
+selecting REF_INT for the clock_config_t.
+
+Alternately, an external 10MHz reference clock can be supplied by soldering a connector.
+
+* Connector J10 (REF_IN) needs MCX connector WM5541-ND or similar
+* Square wave will offer the best phase noise performance, but sinusoid is acceptable
+* Power level: 0 to 15dBm
+* Select REF_SMA in clock_config_t
+
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+PPS - Pulse Per Second
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+An exteral PPS signal for timestamp synchronization can be supplied by soldering a connector.
+
+* Connector J13 (PPS) needs MCX connector WM5541-ND or similar
+* Requires a square wave signal
+* Amplitude: 3.3 to 5Vpp
+
+Test the PPS input with the following app:
+
+* <args> are device address arguments (optional if only one USRP is on your machine)
+
+::
+
+    cd <install-path>/share/uhd/examples
+    ./test_pps_input --args=<args>
diff --git a/host/lib/usrp/dboard/db_xcvr2450.cpp b/host/lib/usrp/dboard/db_xcvr2450.cpp
index 9d25b30a5..70b0bbabd 100644
--- a/host/lib/usrp/dboard/db_xcvr2450.cpp
+++ b/host/lib/usrp/dboard/db_xcvr2450.cpp
@@ -152,12 +152,21 @@ private:
      * \return the rssi in dB
      */
     double get_rssi(void){
+        //*FIXME* RSSI depends on LNA Gain Setting (datasheet pg 16 top middle chart)
+        double max_power;
+        switch(_max2829_regs.rx_lna_gain){
+        case 0:
+        case 1: max_power = 0;    break;
+        case 2: max_power = -15;   break;
+        case 3: max_power = -30.5; break;
+        }
+
         //constants for the rssi calculation
         static const double min_v = 0.5, max_v = 2.5;
         static const double rssi_dyn_range = 60;
         //calculate the rssi from the voltage
         double voltage = this->get_iface()->read_aux_adc(dboard_iface::UNIT_RX, dboard_iface::AUX_ADC_B);
-        return rssi_dyn_range*(voltage - min_v)/(max_v - min_v);
+        return max_power - rssi_dyn_range*(voltage - min_v)/(max_v - min_v);
     }
 };
 
@@ -621,7 +630,7 @@ void xcvr2450::rx_get(const wax::obj &key_, wax::obj &val){
         if (key.name == "lo_locked")
             val = sensor_value_t("LO", this->get_locked(), "locked", "unlocked");
         else if (key.name == "rssi")
-            val = sensor_value_t("RSSI", this->get_rssi(), "dB");
+            val = sensor_value_t("RSSI", this->get_rssi(), "dBm");
         else
             UHD_THROW_INVALID_CODE_PATH();
         return;