Re: [Discuss-gnuradio] Usrp TX mux settings

[Eric Blossom]

On Thu, May 18, 2006 at 08:11:30PM -0400, Garrett McGrath wrote:
> I think i've narrowed down the problems with my code to the mux setting for
> the usrp system.  Is there anywhere you could point me to for a list of
> possible values for that mux, currently i'm just using one i found in a 
> demo
> program but can't seem to find a list of all possible values.
> -Garrett McGrath

Use the source, Luke ;)

>From usrp/host/lib/usrp_standard.h:

Receive mux:

  /*!
   * \brief Set input mux configuration.
   *
   * This determines which ADC (or constant zero) is connected to 
   * each DDC input.  There are 4 DDCs.  Each has two inputs.
   *
   * <pre>
   * Mux value:
   *
   *    3                   2                   1                       
   *  1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
   * +-------+-------+-------+-------+-------+-------+-------+-------+
   * |   Q3  |   I3  |   Q2  |   I2  |   Q1  |   I1  |   Q0  |   I0  |
   * +-------+-------+-------+-------+-------+-------+-------+-------+
   *
   * Each 4-bit I field is either 0,1,2,3
   * Each 4-bit Q field is either 0,1,2,3 or 0xf (input is const zero)
   * All Q's must be 0xf or none of them may be 0xf
   * </pre>
   */
  bool set_mux  (int mux);


Transmit mux:

  /*!
   * \brief Set output mux configuration.
   *
   * <pre>
   *     3                   2                   1                       
   *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
   *  +-------------------------------+-------+-------+-------+-------+
   *  |                               | DAC3  | DAC2  | DAC1  |  DAC0 |
   *  +-------------------------------+-------+-------+-------+-------+
   * 
   *  There are two interpolators with complex inputs and outputs.
   *  There are four DACs.
   * 
   *  Each 4-bit DACx field specifies the source for the DAC and
   *  whether or not that DAC is enabled.  Each subfield is coded
   *  like this: 
   * 
   *     3 2 1 0
   *    +-+-----+
   *    |E|  N  |
   *    +-+-----+
   * 
   *  Where E is set if the DAC is enabled, and N specifies which
   *  interpolator output is connected to this DAC.
   * 
   *   N   which interp output
   *  ---  -------------------
   *   0   chan 0 I
   *   1   chan 0 Q
   *   2   chan 1 I
   *   3   chan 1 Q
   * </pre>
   */
  bool set_mux  (int mux);