usrp2: polished the multi-device addressing scheme and updated docs

1 files changed, 252 insertions, 2 deletions

diff --git a/host/docs/usrp2.rst b/host/docs/usrp2.rst
index af2df66c6..8e5743102 100644
--- a/host/docs/usrp2.rst
+++ b/host/docs/usrp2.rst
@@ -1,5 +1,255 @@
 ========================================================================
-UHD - USRP2 Application Notes
+UHD - USRP2 and N Series Application Notes
 ========================================================================
 
-* `USRP2 and USRP-N Series Application Notes <./usrp_nxxx.html>`_
+.. contents:: Table of Contents
+
+------------------------------------------------------------------------
+Load the images onto the SD card (USRP2 only)
+------------------------------------------------------------------------
+**Warning!**
+Use the usrp2_card_burner.py with caution. If you specify the wrong device node,
+you could overwrite your hard drive. Make sure that --dev= specifies the SD card.
+
+**Warning!**
+It is possible to use 3rd party SD cards with the USRP2.
+However, certain types of SD cards will not interface with the CPLD:
+
+* Cards can be SDHC, which is not a supported interface.
+* Cards can have unexpected timing characteristics.
+
+For these reasons, we recommend that you use the SD card that was supplied with the USRP2.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Use the card burner tool (unix)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+::
+
+    sudo <prefix>/share/uhd/utils/usrp2_card_burner_gui.py
+
+    -- OR --
+
+    cd <prefix>/share/uhd/utils
+    sudo ./usrp2_card_burner.py --dev=/dev/sd<XXX> --fpga=<path_to_fpga_image>
+    sudo ./usrp2_card_burner.py --dev=/dev/sd<XXX> --fw=<path_to_firmware_image>
+
+Use the *--list* option to get a list of possible raw devices.
+The list result will filter out disk partitions and devices too large to be the sd card.
+The list option has been implemented on Linux, Mac OS X, and Windows.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Use the card burner tool (windows)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+::
+
+    <path_to_python.exe> <prefix>/share/uhd/utils/usrp2_card_burner_gui.py
+
+
+------------------------------------------------------------------------
+Load the images onto the on-board flash (USRP-N Series only)
+------------------------------------------------------------------------
+The USRP-N Series can be reprogrammed over the network
+to update or change the firmware and FPGA images.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Use the net burner tool (unix)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+::
+
+    cd <prefix>/share/uhd/utils
+    ./usrp_n2xx_net_burner.py --ip=<ip address> --fw=<path for firmware image>
+    ./usrp_n2xx_net_burner.py --ip=<ip address> --fpga=<path to FPGA image>
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Use the net burner tool (Windows)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+::
+
+    <path_to_python.exe> <prefix>/share/uhd/utils/usrp_n2xx_net_burner.py --ip=<ip address> --fw=<path for firmware image>
+    <path_to_python.exe> <prefix>/share/uhd/utils/usrp_n2xx_net_burner.py --ip=<ip address> --fpga=<path to FPGA image>
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Device recovery and bricking
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Its possible to put the device into an unusable state by loading bad images.
+Fortunately, the USRP-N Series can be booted into a safe (read-only) image.
+Once booted into the safe image, the user can once again load images onto the device.
+
+To boot into the safe image, hold down the reset button while power-cycling the device.
+The reset button is a pushbutton switch (S2) located inside the enclosure.
+
+------------------------------------------------------------------------
+Setup networking
+------------------------------------------------------------------------
+The USRP2 only supports gigabit ethernet,
+and will not work with a 10/100 Mbps interface.
+However, a 10/100 Mbps interface can be connected indirectly
+to a USRP2 through a gigabit ethernet switch.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Setup the host interface
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The USRP2 communicates at the IP/UDP layer over the gigabit ethernet.
+The default IP address of the USRP2 is **192.168.10.2**
+You will need to configure the host's ethernet interface with a static IP address to enable communication.
+An address of **192.168.10.1** and a subnet mask of **255.255.255.0** is recommended.
+
+**Note:**
+When using the UHD, if an IP address for the USRP2 is not specified,
+the software will use UDP broadcast packets to locate the USRP2.
+On some systems, the firewall will block UDP broadcast packets.
+It is recommended that you change or disable your firewall settings.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Multiple device configuration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+For maximum throughput, one ethernet interface per USRP2 is recommended,
+although multiple devices may be connected via a gigabit ethernet switch.
+In any case, each ethernet interface should have its own subnet,
+and the corresponding USRP2 device should be assigned an address in that subnet.
+Example:
+
+**Configuration for USRP2 device 0:**
+
+* Ethernet interface IPv4 address: 192.168.10.1
+* Ethernet interface subnet mask: 255.255.255.0
+* USRP2 device IPv4 address: 192.168.10.2
+
+**Configuration for USRP2 device 1:**
+
+* Ethernet interface IPv4 address: 192.168.20.1
+* Ethernet interface subnet mask: 255.255.255.0
+* USRP2 device IPv4 address: 192.168.20.2
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Change the USRP2's IP address
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+You may need to change the USRP2's IP address for several reasons:
+
+* to satisfy your particular network configuration
+* to use multiple USRP2s on the same host computer
+* to set a known IP address into USRP2 (in case you forgot)
+
+**Method 1:**
+To change the USRP2's IP address
+you must know the current address of the USRP2,
+and the network must be setup properly as described above.
+Run the following commands:
+::
+
+    cd <prefix>/share/uhd/utils
+    ./usrp_burn_mb_eeprom --args=<optional device args> --key=ip-addr --val=192.168.10.3
+
+**Method 2 (Linux Only):**
+This method assumes that you do not know the IP address of your USRP2.
+It uses raw ethernet packets to bypass the IP/UDP layer to communicate with the USRP2.
+Run the following commands:
+::
+
+    cd <prefix>/share/uhd/utils
+    sudo ./usrp2_recovery.py --ifc=eth0 --new-ip=192.168.10.3
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Debugging networking problems
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+**Disable the firewall:**
+If uhd_find_devices gives you nothing
+but uhd_find_devices --args addr=192.168.10.2 yeilds a discovered device,
+then your firewall may be blocking replies to UDP broadcast packets.
+
+**Ping the USRP2:**
+The USRP2 will reply to icmp echo requests.
+::
+
+    ping 192.168.10.2
+
+**Monitor the USRP2:**
+You can read the serial port on the rear of the USRP2
+to get debug verbose from the embedded microcontroller.
+Use a standard USB to 3.3v-level serial converter at 230400 baud.
+The microcontroller prints useful information about IP addresses,
+MAC addresses, control packets, and fast-path settings.
+
+**Monitor the host network traffic:**
+Use wireshark to monitor packets sent to and received from the USRP2.
+
+------------------------------------------------------------------------
+Addressing the device
+------------------------------------------------------------------------
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Single device configuration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+In a single-device configuration,
+the USRP device must have a unique IPv4 address on the host computer.
+The USRP can be identified through its IPv4 address, resolvable hostname, or by other means.
+See the application notes on `device identification <./identification.html>`_.
+Use this addressing scheme with the *single_usrp* interface.
+
+Example device address string representation for a USRP2 with IPv4 address 192.168.10.2
+
+::
+
+    addr=192.168.10.2
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Multiple device configuration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+In a multi-device configuration,
+each USRP device must have a unique IPv4 address on the host computer.
+The device address parameter keys must be suffixed with the device index.
+Each parameter key should be of the format <key><index>.
+Use this addressing scheme with the *multi_usrp* interface.
+
+* The order in which devices are indexed corresponds to the indexing of the transmit and receive channels.
+* The key indexing provides the same granularity of device identification as in the single device case.
+
+Example device address string representation for 2 USRP2s with IPv4 addresses 192.168.10.2 and 192.168.20.2
+::
+
+    addr0=192.168.10.2, addr1=192.168.20.2
+
+------------------------------------------------------------------------
+Hardware setup notes
+------------------------------------------------------------------------
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Front panel LEDs
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The LEDs on the front panel can be useful in debugging hardware and software issues.
+The LEDs reveal the following about the state of the device:
+
+* **LED A:** transmitting
+* **LED B:** serdes link
+* **LED C:** receiving
+* **LED D:** firmware loaded
+* **LED E:** reference lock
+* **LED F:** CPLD loaded
+
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Ref Clock - 10MHz
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Using an external 10MHz reference clock, square wave will offer the best phase
+noise performance, but sinusoid is acceptable.  The reference clock requires the following power level:
+
+* **USRP2** 5 to 15dBm
+* **N2XX** 0 to 15dBm
+
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+PPS - Pulse Per Second
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Using a PPS signal for timestamp synchronization requires a square wave signal with the following amplitude:
+
+* **USRP2** 5Vpp
+* **N2XX** 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 <prefix>/share/uhd/examples
+    ./test_pps_input --args=<args>