x300: Enable power reference API

This enables the power calbration API for X300 and X310. The
uhd_power_cal.py script will be able to create calibration files for
X300 series USRPs.

The multi_usrp calls *_power_reference  will be functional, assuming
there is calibration data available for the given system.

2 files changed, 37 insertions, 0 deletions

diff --git a/host/docs/twinrx.dox b/host/docs/twinrx.dox
index 2175c13ff..d8dd20f6d 100644
--- a/host/docs/twinrx.dox
+++ b/host/docs/twinrx.dox
@@ -101,5 +101,33 @@ gain on the second channel could be significantly lower or higher than expected.
 will increase in comparison to the direct antenna mapping so the phase of the received signal will be different
 depending on the antenna mapping.
 
+\subsection twinrx_power_cal Power Calibration
+
+The X300/X310 motherboards support power-calibrating the daughterboards, and
+therefore TwinRX can also make use of this calibration API (see also \ref page_power).
+
+However, unlike other daughterboards, the relationship between actual, received
+power, and power measured at the ADC depend on more parameters than with the
+other daughterboards. First of all, the TwinRX has two complete analog receiver
+chains, unlike all the other daughterboards. Both receiver chains can be connected
+to any RF input, which already increases the number of combinations that need to
+be calibrated. Furthermore, the RF paths inside the daughterboard have an
+optional switch, which allows both receivers to receive from the same input, at
+different frequencies.
+
+
+single chan
+
+x3xx_power_cal_rx_rx1 + serial:{0, 1}
+x3xx_power_cal_rx_rx2 + serial:{0, 1}
+
+dual chan
+
+
+x3xx_power_cal_rx_rx1 + serial:{00, 11}
+x3xx_power_cal_rx_rx2 + serial:{00, 11}
+
+
+
 */
 // vim:ft=doxygen:
diff --git a/host/docs/usrp_x3x0.dox b/host/docs/usrp_x3x0.dox
index 54b0043f3..c95ddd1b9 100644
--- a/host/docs/usrp_x3x0.dox
+++ b/host/docs/usrp_x3x0.dox
@@ -773,6 +773,15 @@ Further information on how to use Chipscope can be found in the Xilinx Chipscope
 
 \section x3x0_misc Miscellaneous
 
+\subsection x3x0_misc_power Power API
+
+The X300 series support the UHD power calibration API (see: \ref page_power).
+Calibration data is daughterboard-specific, i.e., the daughterboard serial is
+used to map calibration data to a serial.
+
+Daughterboards have to be manually calibrated using a calibrated power meter or
+signal generator.
+
 \subsection x3x0_misc_settings Configuring the device in an application
 
 During runtime, the device can be configured in several different ways.