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Diffstat (limited to 'host/docs/usrp2.rst')
| -rw-r--r-- | host/docs/usrp2.rst | 67 |
1 files changed, 53 insertions, 14 deletions
diff --git a/host/docs/usrp2.rst b/host/docs/usrp2.rst index 09987b3fa..d3ae1dec7 100644 --- a/host/docs/usrp2.rst +++ b/host/docs/usrp2.rst @@ -11,8 +11,7 @@ Building firmware and FPGA images ^^^^^^^^^^^^^^^^^^ FPGA Image ^^^^^^^^^^^^^^^^^^ -Xilinx ISE 10.1 is required to build the FPGA image for the USRP2 -(newer version of ISE are known to build buggy images). +Xilinx ISE 10.1 and up is required to build the FPGA image for the USRP2. The build requires that you have a unix-like environment with make. Make sure that xtclsh from the Xilinx ISE bin directory is in your $PATH. @@ -150,6 +149,40 @@ MAC addresses, control packets, and fast-path settings. Use wireshark to monitor packets sent to and received from the USRP2. ------------------------------------------------------------------------ +Addressing the device +------------------------------------------------------------------------ + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Single device configuration +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +A USRP2 can be identified though its IPv4 address or resolvable hostname. +The USRP2 device is referenced through the "addr" key in the device address. +Use this addressing scheme with the *simple_usrp* interface. + +The device address string representation for a USRP2 with IPv4 address 192.168.10.2 + +:: + + addr=192.168.10.2 + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Soft-MIMO configuration +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +In a soft-mimo configuration, each USRP2 must have a unique IPv4 address (per computer) +and be attached to its own dedicated network port. +The value for the addr key is a white-space separated list +of IPv4 addresses or resolvable hostnames. +The first address in the list will represent channel 0, +the second channel 1, and so on... +Use this addressing scheme with the *mimo_usrp* interface. + +The device address string representation for 2 USRP2s with IPv4 addresses 192.168.10.2 and 192.168.20.2 +:: + + addr=192.168.10.2 192.168.20.2 + + +------------------------------------------------------------------------ Resize the send and receive buffers ------------------------------------------------------------------------ It may be useful increase the size of the socket buffers to @@ -158,10 +191,27 @@ buffer incoming samples faster than they can be processed. However, if you application cannot process samples fast enough, no amount of buffering can save you. +By default, the UHD will try to request a reasonably large buffer size for both send and receive. +A warning will be printed on instantiation if the actual buffer size is insufficient. +See the OS specific notes below: + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +OS specific notes +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +On linux, the maximum buffer sizes are capped by the sysctl values +**net.core.rmem_max** and **net.core.wmem_max**. +To change the maximum values, run the following commands: +:: + + sudo sysctl -w net.core.rmem_max=<new value> + sudo sysctl -w net.core.wmem_max=<new value> + +Set the values permanently by editing */etc/sysctl.conf* + ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Device address params ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -To set the size of the buffers, +To manually set the size of the buffers, the usrp2 will accept two optional parameters in the device address. Each parameter will accept a numeric value for the number of bytes. @@ -172,14 +222,3 @@ Example, set the args string to the following: :: addr=192.168.10.2, recv_buff_size=100e6 - -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -OS specific notes -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -On linux, the maximum buffer sizes are capped by the sysctl values -**net.core.rmem_max** and **net.core.wmem_max**. -To change the maximum values, run the following commands: -:: - - sudo sysctl -w net.core.rmem_max=<new value> - sudo sysctl -w net.core.wmem_max=<new value> |