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| author | Martin Braun <martin.braun@ettus.com> | 2019-02-26 16:20:48 -0800 |
|---|---|---|
| committer | Michael West <michael.west@ettus.com> | 2019-03-05 10:33:21 -0800 |
| commit | 75236de2ee8c7ea4df8d2511b1df7dc24a8de91a (patch) | |
| tree | 7cea7ec205447e65bfa60d496abc7e028f57ccce | |
| parent | dd61c2376f62b42e06844fd23522138eb7c01a04 (diff) | |
| download | uhd-75236de2ee8c7ea4df8d2511b1df7dc24a8de91a.tar.gz uhd-75236de2ee8c7ea4df8d2511b1df7dc24a8de91a.tar.bz2 uhd-75236de2ee8c7ea4df8d2511b1df7dc24a8de91a.zip | |
docs: x300: Add notes on external reference frequencies
| -rw-r--r-- | host/docs/configuration.dox | 1 | ||||
| -rw-r--r-- | host/docs/usrp_x3x0.dox | 13 |
2 files changed, 12 insertions, 2 deletions
diff --git a/host/docs/configuration.dox b/host/docs/configuration.dox index ccc3129fb..480410d5c 100644 --- a/host/docs/configuration.dox +++ b/host/docs/configuration.dox @@ -28,6 +28,7 @@ and possible more options. ignore-cal-file | Ignores existing device calibration files | All Devices with cal-file support| See \ref ignore_cal_file master_clock_rate | Master Clock Rate in Hz | X3x0, B2x0, B1x0, E3x0, E1x0, N3xx | master_clock_rate=16e6 dboard_clock_rate | Daughterboard clock rate in Hz | X3x0 | dboard_clock_rate=50e6 + system_ref_rate | Frequency of external reference | X3x0 | system_ref_rate=11.52e6 mcr | Override master clock rate settings (see \ref usrp1_hw_extclk) | USRP1 | mcr=52e6 niusrprpc_port | RPC Port for NI USRP RIO | X3x0 | niusrprpc_port=5445 system_ref_rate | Reference Clock Rate in Hz | X3x0 | system_ref_rate=10e6 diff --git a/host/docs/usrp_x3x0.dox b/host/docs/usrp_x3x0.dox index e8d1af24e..d55643e1f 100644 --- a/host/docs/usrp_x3x0.dox +++ b/host/docs/usrp_x3x0.dox @@ -15,7 +15,7 @@ More information: - Dual SFP+ Transceivers (can be used with 1 GigE, 10 GigE) - PCI Express over cable (MXI) gen1 x4 - External PPS input & output - - External 10 MHz input & output + - External reference (10 MHz, 11.52 MHz, 23.04 MHz, or 30.72 MHz) input & output - Expandable via 2nd SFP+ interface - Supported master clock rates: 200 MHz and 184.32 MHz - Variable daughterboard clock rates @@ -663,12 +663,21 @@ Afterward, power-cycle your X-Series device for the changes to take effect. - **PPS/TRIG IN**: Input port for the PPS signal - **GPS**: Connection for the GPS antenna -\subsection x3x0_hw_x3x0_hw_ref10M Ref Clock - 10 MHz +\subsection x3x0_hw_x3x0_hw_ref10M Ref Clock (10 MHz or other frequency) Using an external 10 MHz reference clock, a square wave will offer the best phase noise performance, but a sinusoid is acceptable. The power level of the reference clock must exceed +15 dBm. +The following reference frequencies are supported: +- 10 MHz +- 11.52 MHz +- 23.04 MHz +- 30.72 MHz + +If the external reference clock is not 10 MHz, the `system_ref_rate` device arg +must be provided. + To use the external reference in your UHD session, make sure to either call uhd::usrp::multi_usrp::set_clock_source() or specify `clock_source=external` in your device args. |