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AD9361 no-OS manual gain control

Question asked by pharbour on Jun 20, 2014
Latest reply on Jun 26, 2014 by mhennerich

Hi,

 

I am using the AD9361 on an Altera SoC FPGA platform running the no-OS drivers.  All basic functions within the no-OS console app are running correctly [thanks for supplying this ].  I have been trying to use manual gain control mode in the device and I am seeing warning logs that do not make sense to me.  I will describe how I configure InitParam section and then the warnings I am seeing from ad9361.c functions.  I must just have something setup wrong and I would appreciate guidance from someone familiar with how to use manual gain control mode.

 

InitParam:

 

     0,     //split_gain_table_mode_enable *** adi,split-gain-table-mode-enable

 

     /* Gain Control */

     0,     //gc_rx1_mode *** adi,gc-rx1-mode

     2,     //gc_rx2_mode *** adi,gc-rx2-mode

 

     /* Gain MGC Control */

     2,     //mgc_dec_gain_step *** adi,mgc-dec-gain-step

     2,     //mgc_inc_gain_step *** adi,mgc-inc-gain-step

     0,     //mgc_rx1_ctrl_inp_enable *** adi,mgc-rx1-ctrl-inp-enable

     0,     //mgc_rx2_ctrl_inp_enable *** adi,mgc-rx2-ctrl-inp-enable

     0,     //mgc_split_table_ctrl_inp_gain_mode *** adi,mgc-split-table-ctrl-inp-gain-mode

 

 

I believe this should set RX channel 1 in manual gain control mode using SPI writes for gain control (not CTRL_IN hardware signalling).  The ad9361_setup function call completes successfully (without any warnings that are obvious to me).  Upon starting the command console I check rx1_gc and rx2_gc modes and rx1_rf_gain value, I get the expected results...

 

rx1_gc_mode?

rx1_gc_mode=0

rx2_gc_mode?

rx2_gc_mode=2

rx1_rf_gain?

ad9361_rfpll_recalc_rate: Parent Rate 40000000 Hz

rx1_rf_gain=71

 

then I attempt to set manual gain on rx1 and I get the following warnings...

 

rx1_rf_gain=40

Nothing to do, device is already in state a

Ignoring lmt/lpf/digital gains in Single Table mode

ad9361_rfpll_recalc_rate: Parent Rate 40000000 Hz

rx1_rf_gain=40

 

I am confused about the 'Ignoring lmt/lpf/digital gains in Single Table mode' warning because I believe I have the device configured for RX full gain table mode.  But, somehow gain table values only supported in split table mode are active.  Is this warning expected in manual gain control mode?  If not, what should I check to reveal if I have set something up improperly?

 

 

Thanks in advance,

 

Pete

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