diff options
Diffstat (limited to 'host/docs/usrp_e3x0.dox')
| -rw-r--r-- | host/docs/usrp_e3x0.dox | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/host/docs/usrp_e3x0.dox b/host/docs/usrp_e3x0.dox index 01b0fd929..68ffc0122 100644 --- a/host/docs/usrp_e3x0.dox +++ b/host/docs/usrp_e3x0.dox @@ -132,7 +132,7 @@ which should return 'arm-oe-linux-gnueabi'. -# Setup your environment as described in \ref e3x0_sdk_usage -# Type the following in the build directory (assuming a build in host/build): - $ cmake -DCMAKE_TOOLCHAIN_FILE=<youruhdsrc>/host/cmake/Toolchains/oe-sdk_cross.cmake -DENABLE_E300=On .. + $ cmake -DCMAKE_TOOLCHAIN_FILE=<youruhdsrc>/host/cmake/Toolchains/oe-sdk_cross.cmake -DCMAKE_INSTALL_PREFIX=/usr -DENABLE_E300=ON .. $ make \subsubsection e3x0_sdk_usage_gnuradio Building GNU Radio @@ -143,7 +143,7 @@ which should return 'arm-oe-linux-gnueabi'. \code{.sh} $ mkdir build-arm -$ cmake -Wno-dev -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchains/oe-sdk_cross.cmake \-DCMAKE_INSTALL_PREFIX=/usr -DENABLE_GR_VOCODER=OFF -DGR_ENABLE_ATSC=OFF \ +$ cmake -Wno-dev -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchains/oe-sdk_cross.cmake \-DCMAKE_INSTALL_PREFIX=/usr -DENABLE_GR_VOCODER=OFF -DENABLE_GR_ATSC=OFF \ -DENABLE_GR_DTV=OFF -DENABLE_DOXYGEN=OFF ../ \endcode @@ -274,8 +274,18 @@ You may need to change the USRP's IP address for several reasons: - **USB**: USB 2.0 Port - **SERIAL**: Micro USB connection for serial uart console +\subsection e3x0_hw_sync Clock and Time Synchronization +Unlike most USRP devices, the E310 does not have independent reference clock and time source inputs. +It is possible, however, to discipline the internal reference clock using an external time (PPS) source +connected to the SYNC input pin. The E310 FPGA has a subsystem that can use the PPS signal from the +SYNC pin or the internal GPS to align edges of the reference clock to edges of a shared PPS signal. +This alignment happens automatically when the time source in UHD is set to "gpsdo" or "external". +Please note that because the SYNC input can only accept a PPS signal, the only supported value for +the reference clock source is "internal". + + \subsection e3x0_hw_pps PPS - Pulse Per Second -Using a PPS signal for timestamp synchronization requires a square wave signal with the following a 5Vpp amplitude. +Using a PPS signal for timestamp synchronization requires a LVCMOS or a 5V logic input signal. An external PPS can be used to discipline the internal reference clock. This feature is automatically enabled with the time source is set to "external". |