/*! \page page_dboards Daughterboards

\tableofcontents

\section dboards Daughterboard Properties


The following contains interesting notes about each daughterboard.
Eventually, this page will be expanded to list out the full properties
of each board as well.

\subsection dboards_basicrx Basic RX and LFRX

The Basic RX and LFRX boards have four modes of operation:

-   **Frontend A:** real signal on antenna RXA
-   **Frontend B:** real signal on antenna RXB
-   **Frontend AB:** quadrature frontend using both antennas (IQ)
-   **Frontend BA:** quadrature frontend using both antennas (QI)

The way in which you select the mode depends on the USRP type. On the X310,
selecting the mode is done using the antenna API:

```cpp
auto usrp = uhd::usrp::multi_usrp::make("type=x300");
usrp->set_rx_antenna("A"); // Disable RXB port
```

On the USRP2, the N200 series, the B100 series, the E100, and the USRP1 the mode
depends on the subdev spec applied:

```cpp
auto usrp = uhd::usrp::multi_usrp::make("type=usrp2");
usrp->set_rx_subdev_spec("A:A"); // Disable RXB port
```

The boards have no tunable elements or programmable gains. Through the
magic of aliasing, you can down-convert signals greater than the Nyquist
rate of the ADC.

BasicRX Bandwidth:

-   **For Real-Mode (A or B frontend)**: 250 MHz
-   **For Complex (AB or BA frontend)**: 500 MHz

LFRX Bandwidth:

-   **For Real-Mode (A or B frontend)**: 33 MHz
-   **For Complex (AB or BA frontend)**: 66 MHz

\subsection dboards_basictx Basic TX and LFTX

The Basic TX and LFTX boards have 4 frontends:

-   **Frontend A:** real signal on antenna TXA
-   **Frontend B:** real signal on antenna TXB
-   **Frontend AB:** quadrature frontend using both antennas (IQ)
-   **Frontend BA:** quadrature frontend using both antennas (QI)

The boards have no tunable elements or programmable gains. Through the
magic of aliasing, you can up-convert signals greater than the Nyquist
rate of the DAC.

BasicTX Bandwidth:

-   **For Real-Mode (A or B frontend**): 250 MHz
-   **For Complex (AB or BA frontend)**: 500 MHz

LFTX Bandwidth:

-   **For Real-Mode (A or B frontend)**: 33 MHz
-   **For Complex (AB or BA frontend)**: 66 MHz

\subsection dboards_dbsrx DBSRX

The DBSRX board has 1 quadrature frontend. It defaults to direct
conversion but can use a low IF through lo_offset in uhd::tune_request_t.

Receive Antennas: **J3**

-   **Frontend 0:** Complex baseband signal from antenna J3

The board has no user selectable antenna setting.

Receive Gains:

-   **GC1**, Range: 0-56dB
-   **GC2**, Range: 0-24dB

Bandwidth: 8 MHz - 66 MHz

Sensors:

-   **lo_locked**: boolean for LO lock state

\subsection dboards_dbsrx2 DBSRX2

The DBSRX2 board has 1 quadrature frontend. It defaults to direct
conversion, but can use a low IF through `lo_offset` in uhd::tune_request_t.

Frequency Range: 800 MHz to 2.3 GHz

Receive Antennas: **J3**

-   **Frontend 0:** Complex baseband signal from antenna J3

The board has no user-selectable antenna setting.

Receive Gains:

-   **GC1**, Range: 0-73dB
-   **BBG**, Range: 0-15dB

Bandwidth (Hz): 8 MHz-80 MHz

Sensors:

-   **lo_locked**: boolean for LO lock state

Notes:
- When used in the X3x0, set the daughterboard clock rate to 100 MHz (see \ref config_devaddr)

\subsection dboards_rfx RFX Series

The RFX Series boards have 2 quadrature frontends: Transmit and Receive.
Transmit defaults to low IF, and Receive defaults to direct conversion.
The IF can be adjusted through lo_offset in uhd::tune_request_t.

The RFX Series boards have independent receive and transmit LO's and
synthesizers allowing full-duplex operation on different transmit and
receive frequencies.

Transmit Antennas: **TX/RX**

Receive Antennas: **TX/RX** or **RX2**

-   **Frontend 0:** Complex baseband signal for selected antenna

The user may set the receive antenna to be TX/RX or RX2. However, when
using an RFX board in full-duplex mode, the receive antenna will always
be set to RX2, regardless of the settings.

Receive Gains: **PGA0**, Range: 0-70dB (except RFX400 range is 0-45dB)

Bandwidth:

-   **RX**: 40 MHz
-   **TX**: 40 MHz

Sensors:

-   **lo_locked**: boolean for LO lock state

\subsection dboards_xcvr XCVR 2450

\b Note: The XCVR2450 is not compatible with the X3x0-Series.

The XCVR2450 has 2 quadrature frontends, one transmit, one receive.
Transmit and Receive default to direct conversion but can be used in low
IF mode through lo_offset in uhd::tune_request_t.

The XCVR2450 has a non-contiguous tuning range consisting of a high band
(4.9-6.0 GHz) and a low band (2.4-2.5 GHz).

Transmit Antennas: **J1** or **J2**

Receive Antennas: **J1** or **J2**

-   **Frontend 0:** Complex baseband signal for selected antenna

The XCVR2450 uses a common LO for both receive and transmit. Even though
the API allows the RX and TX LOs to be individually set, a change of one
LO setting will be reflected in the other LO setting.

The XCVR2450 does not support full-duplex mode, attempting to operate in
full-duplex will result in transmit-only operation.

Transmit Gains:

-   **VGA**, Range: 0-30dB
-   **BB**, Range: 0-5dB

Receive Gains:

-   **LNA**, Range: 0-30.5dB
-   **VGA**, Range: 0-62dB

Bandwidths:

-   **RX**: 15 MHz, 19 MHz, 28 MHz, 36 MHz; (each +-0, 5, or 10%)
-   **TX**: 24 MHz, 36 MHz, 48 MHz

Sensors:

-   **lo_locked**: boolean for LO lock state
-   **rssi**: float for rssi in dBm

\subsection dboards_wbx WBX Series

Features:

-   2 quadrature frontends (1 transmit, 1 receive)
    -   Defaults to direct conversion
    -   Can be used in low IF mode through lo_offset with uhd::tune_request_t
-   Independent receive and transmit LO's and synthesizers
    -   Allows for full-duplex operation on different transmit and receive frequencies
    -   Can be set to use Integer-N tuning for better spur performance
        with uhd::tune_request_t

Frequency Range: 50 MHz to 2.2 GHz

Transmit Antennas: **TX/RX**

Receive Antennas: **TX/RX** or **RX2**

-   **Frontend 0:** Complex baseband signal for selected antenna

-   **Note:** The user may set the receive antenna to be TX/RX or RX2.
    However, when using a WBX board in full-duplex mode, the receive
    antenna will always be set to RX2, regardless of the settings.

Transmit Gains: **PGA0**, Range: 0-25dB

Receive Gains: **PGA0**, Range: 0-31.5dB

Bandwidths:

-   **WBX**: 40 MHz, RX & TX
-   **WBX-120**: 120 MHz, RX & TX

Sensors:

-   **lo_locked**: boolean for LO lock state

\subsection dboards_sbx SBX Series

Features:

-   2 quadrature frontends (1 transmit, 1 receive)
    -   Defaults to direct conversion
    -   Can be used in low IF mode through lo_offset with uhd::tune_request_t
-   Independent receive and transmit LO's and synthesizers
    -   Allows for full-duplex operation on different transmit and
        receive frequencies
    -   Can be set to use Integer-N tuning for better spur performance with uhd::tune_request_t

Frequency Range: 400 MHz to 4.4 GHz

Transmit Antennas: **TX/RX**

Receive Antennas: **TX/RX** or **RX2**

-   **Frontend 0:** Complex baseband signal for selected antenna

-   **Note:** The user may set the receive antenna to be TX/RX or RX2.
    However, when using an SBX board in full-duplex mode, the receive
    antenna will always be set to RX2, regardless of the settings.

Transmit Gains: **PGA0**, Range: 0-31.5dB

Receive Gains: **PGA0**, Range: 0-31.5dB

Bandwidths:

-   **SBX**: 40 MHz, RX & TX
-   **SBX-120**: 120 MHz, RX & TX

Sensors:

-   **lo_locked**: boolean for LO lock state

LEDs:

-   All LEDs flash when daughterboard control is initialized
-   **TX LD**: Transmit Synthesizer Lock Detect
-   **TX/RX**: Receiver on TX/RX antenna port (No TX)
-   **RX LD**: Receive Synthesizer Lock Detect
-   **RX1/RX2**: Receiver on RX2 antenna port

\subsection dboards_cbx CBX Series

Features:
-   2 quadrature frontends (1 transmit, 1 receive)
    -   Defaults to direct conversion
    -   Can be used in low IF mode through lo_offset with uhd::tune_request_t
-   Independent receive and transmit LO's and synthesizers
    -   Allows for full-duplex operation on different transmit and
        receive frequencies
    -   Can be set to use Integer-N tuning for better spur performance with uhd::tune_request_t

Frequency Range: 1.2 GHz to 6 GHz

Transmit Antennas: **TX/RX**

Receive Antennas: **TX/RX** or **RX2**

-   **Frontend 0:** Complex baseband signal for selected antenna

-   **Note:** The user may set the receive antenna to be TX/RX or RX2.
    However, when using a CBX board in full-duplex mode, the receive
    antenna will always be set to RX2, regardless of the settings.

Transmit Gains: **PGA0**, Range: 0-31.5dB

Receive Gains: **PGA0**, Range: 0-31.5dB

Bandwidths:

-   **CBX**: 40 MHz, RX & TX
-   **CBX-120**: 120 MHz, RX & TX

Sensors:

-   **lo_locked**: boolean for LO lock state

LEDs:

-   All LEDs flash when daughterboard control is initialized
-   **TX LD**: Transmit Synthesizer Lock Detect
-   **TX/RX**: Receiver on TX/RX antenna port (No TX)
-   **RX LD**: Receive Synthesizer Lock Detect
-   **RX1/RX2**: Receiver on RX2 antenna port

\subsection dboards_ubx UBX Series

Features:
-   2 quadrature frontends (1 transmit, 1 receive)
    -   Defaults to direct conversion
    -   Can be used in low IF mode through lo_offset with uhd::tune_request_t
-   Independent receive and transmit LO's and synthesizers
    -   Allows for full-duplex operation on different transmit and
        receive frequencies
    -   Can be set to use Integer-N tuning for better spur performance with uhd::tune_request_t

Frequency Range: 10 MHz to 6 GHz

Transmit Antennas: **TX/RX**

Receive Antennas: **TX/RX** or **RX2**

-   **Frontend 0:** Complex baseband signal for selected antenna

-   **Note:** The user may set the receive antenna to be TX/RX or RX2.
    However, when using a UBX board in full-duplex mode, the receive
    antenna will always be set to RX2, regardless of the settings.

Transmit Gains: **PGA0**, Range: 0-31.5dB

Receive Gains: **PGA0**, Range: 0-31.5dB

Bandwidths:

-   **UBX**: 40 MHz, RX & TX
-   **UBX-160**: 160 MHz, RX & TX

Sensors:

-   **lo_locked**: boolean for LO lock state

LEDs:

-   **LOCK**: Synthesizer Lock Detect
-   **TX/RX TXD**: Transmitting on TX/RX antenna port
-   **TX/RX RXD**: Receiving on TX/RX antenna port
-   **RX2 RXD**: Receiving on RX2 antenna port


Notes:
- When used in the X300/X310 at frequencies below 1 GHz, it is necessary to
  reduce the daughterboard clock rate to 20 MHz to achieve phase
  synchronization and best RF performance (see \ref config_devaddr).

\subsection dboards_twinrx TwinRX

Features:
-  2 super-heterodyne frontends (2 receive, 0 transmit)
   - Digital IF of +/- 50 MHz
- Supports sharing one channel's LO to the other or the use of an external LO
   - Allows multiple channels and daughterboards to be frequency and phase synchronized

Frequency Range: 10 MHz to 6 GHz

Receive Antennas: **RX1** and **RX2**

Receive Gain: 0-93dB

The TwinRX daughterboard only works with the X300/X310 motherboards, and
requires a master clock rate of 200 MHz.

More information:
\li \subpage page_twinrx

\subsection dboards_tvrx TVRX

The TVRX board has 1 real-mode frontend. It is operated at a low IF.

Receive Antennas: RX

-   **Frontend 0:** real-mode baseband signal from antenna RX

Receive Gains:

-   **RF**, Range: -13.3-50.3dB (frequency-dependent)
-   **IF**, Range: -1.5-32.5dB

Bandwidth: 6 MHz

\subsection dboards_tvrx2 TVRX2

The TVRX2 board has 2 real-mode frontends. It is operated at a low IF.

Frequency Range: 50 MHz to 860 MHz

Receive Frontends:

-   **Frontend RX1:** real-mode baseband from antenna J100
-   **Frontend RX2:** real-mode baseband from antenna J140

Note: The TVRX2 has always-on AGC; the software controllable gain is the
final gain stage which controls the AGC set-point for output to ADC.

Receive Gains:

-   **IF**, Range: 0.0-30.0dB

Bandwidth: 1.7 MHz, 6 MHz, 7 MHz, 8 MHz, 10 MHz

Sensors:

-   **lo_locked**: boolean for LO lock state
-   **rssi**: float for measured RSSI in dBm
-   **temperature**: float for measured temperature in degC

Notes:

- The TVRX2 requires a 64 MHz, 100 MHz or 200 MHz reference clock. On the X3x0,
  set the daughterboard clock rate accordingly (see \ref config_devaddr), typically
  to 100 MHz.

\subsection dboards_e300 E310 MIMO XCVR board

Please refer to \ref e3x0_dboard_e310.

\subsection dboards_n310 N310 XCVR board

Please refer to \ref n3xx_mg.

\subsection dboards_clock_rate Daughterboard reference clock

The USRP motherboard provides a reference clock to the daughterboards, which
the daughterboards will use to generate LO signals or anything else that
requires a reference clock.

The X3x0 has a programmable reference clock, which might have to be changed
depending on various applications (see the daughterboard sections above).
However, it can provide only one daughterboard clock per device, which can
lead to conflicts. It might not be possible to use a specific daughterboard
together with all others.

\subsection dboards_dbsrxmod DBSRX - Modifying for other boards that USRP1

Due to different clocking capabilities, the DBSRX will require
modifications to operate on a non-USRP1 motherboard. On a USRP1
motherboard, a divided clock is provided from an FPGA pin because the
standard daughterboard clock lines cannot provided a divided clock.
However, on other USRP motherboards, the divided clock is provided over
the standard daughterboard clock lines.

\subsubsection dboards_dbsrxmod_1 Step 1: Move the clock configuration resistor

Remove **R193** (which is 10 Ohms, 0603 size), and put it on **R194**, which is
empty. This is made somewhat more complicated by the fact that the silkscreen
is not clear in that area. **R193** is on the back, immediately below the large
beige connector, **J2**. **R194** is just below, and to the left of **R193**.

The silkscreen for **R193** is ok, but for **R194**, it is upside down, and
partially cut off. If you lose **R193**, you can use anything from 0 to 10 Ohms
there.

\subsubsection dboards_dbsrxmod_2 Step 2: Burn a new daughterboard id into the EEPROM

With the daughterboard plugged-in, run the following commands:

    cd <install-path>/lib/uhd/utils
    ./usrp_burn_db_eeprom --id=0x000d --unit=RX --args=<args> --slot=<slot>

-   `<args>` are device address arguments (optional if only one USRP
    device is on your machine)
-   `<slot>` is the name of the daughterboard slot (optional if the
    USRP device has only one slot)

\subsection dboards_rfxmod RFX - Modify to use motherboard oscillator

Older RFX boards require modifications to use the motherboard
oscillator. If this is the case, UHD software will print a warning about
the modification. Please follow the modification procedures below:

- Step 1: Disable the daughterboard clocks**

Move **R64** to **R84**. Move **R142** to **R153**.

- Step 2: Connect the motherboard blocks

Move **R35** to **R36**. Move **R117** to **R115**. These are all 0-Ohm,
so if you lose one, just short across the appropriate pads.

- Step 3: Burn the appropriate daughterboard ID into the EEPROM

With the daughterboard plugged in, run the following commands: :

    cd <install-path>/lib/uhd/utils
    ./usrp_burn_db_eeprom --id=<rx_id> --unit=RX --args=<args> --slot=<slot>
    ./usrp_burn_db_eeprom --id=<tx_id> --unit=TX --args=<args> --slot=<slot>

-   `<rx_id>` choose the appropriate RX ID for your daughterboard
    -   **RFX400:** 0x0024
    -   **RFX900:** 0x0025
    -   **RFX1800:** 0x0034
    -   **RFX1200:** 0x0026
    - **RFX2400:** 0x0027
-   `<tx_id>` choose the appropriate TX ID for your daughterboard
    -   **RFX400:** 0x0028
    -   **RFX900:** 0x0029
    -   **RFX1800:** 0x0035
    -   **RFX1200:** 0x002a
    -   **RFX2400:** 0x002b
-   `<args>` are device address arguments (optional if only one USRP device is on your machine)
-   `<slot>` is the name of the daughterboard slot (optional if the USRP device has only one slot)


*/
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