Hello All,
I’m using AD9371 for advanced Wi-Fi prototyping. Hence I had to change 122.88MHz VCXO on evaluation board to 80MHz so I can achieve integer multiples of 20MHz sampling required for 802.11 signal processing.
By doing so, I discover a number of issues, particularly with initial calibration routine in AD9371 firmware and driver. Below are details of my discovery and workaround I find to make it work. Could you please review it and subject the better way to make AD9371 work for 80MHz sampling clk, Thanks, Mikhail.
Here are details:
1.By enabling ad9371 evaluation board to run at 80MHz clk I discover a multiple issues with Filter Designer for AD9371, AD9371 calibration firmware routine and a driver. While I found a workaround, we asking to address this issue as it preventing us to use AD9371 in normal operation mode.
2.Attached are word document and supporting files (.m file, profile & .dts) with necessary information to make ad9371 work 80MHz clk so I&Q sampling rate is integer multiplier of 20MHz (as it used for 802.11/WI-FI).
<profile AD9371 version=0 name=Rx 40, IQrate 80.000> <clocks> <deviceClock_kHz=320000> <clkPllVcoFreq_kHz=9600000> <clkPllVcoDiv=3> <clkPllHsDiv=4> </clocks> <rx> <adcDiv=1> <rxFirDecimation=2> <rxDec5Decimation=5> <enHighRejDec5=1> <rhb1Decimation=1> <iqRate_kHz=80000> <rfBandwidth_Hz=40000000> <rxBbf3dBCorner_kHz=40000> <filter FIR gain=-6 num=48> 1 7 3 -20 -38 10 107 100 -122 -334 -113 506 718 -166 -1391 -1095 1231 3033 981 -4224 -6482 219 14325 26107 26107 14325 219 -6482 -4224 981 3033 1231 -1095 -1391 -166 718 506 -113 -334 -122 100 107 10 -38 -20 3 7 1 </filter> <adc-profile num=16> 900 559 201 98 1280 199 1522 98 860 25 529 37 48 26 15 196 </adc-profile> </rx> <obs> <adcDiv=1> <rxFirDecimation=2> <rxDec5Decimation=5> <enHighRejDec5=1> <rhb1Decimation=1> <iqRate_kHz=80000> <rfBandwidth_Hz=40000000> <rxBbf3dBCorner_kHz=20000> <filter FIR gain=-6 num=48> -1 10 10 -22 -60 -6 143 171 -129 -485 -245 660 1099 -74 -1954 -1784 1506 4443 1920 -5737 -10210 -2631 15550 31189 31189 15550 -2631 -10210 -5737 1920 4443 1506 -1784 -1954 -74 1099 660 -245 -485 -129 171 143 -6 -60 -22 10 10 -1 </filter> <adc-profile num=16> 900 559 201 98 1280 199 1522 98 860 25 529 37 48 26 15 196 </adc-profile> <lpbk-adc-profile num=16> 922 550 201 98 1280 112 1505 53 864 14 533 40 48 26 15 197 </lpbk-adc-profile> </obs> <sniffer> <adcDiv=1> <rxFirDecimation=2> <rxDec5Decimation=5> <enHighRejDec5=1> <rhb1Decimation=2> <iqRate_kHz=40000> <rfBandwidth_Hz=20000000> <rxBbf3dBCorner_kHz=20000> <filter FIR gain=-6 num=72> -9 12 18 17 -17 -49 -45 21 99 105 -11 -171 -215 -36 258 390 149 -343 -648 -371 394 1003 763 -357 -1476 -1425 138 2113 2589 489 -3082 -5079 -2537 4990 14500 21095 21095 14500 4990 -2537 -5079 -3082 489 2589 2113 138 -1425 -1476 -357 763 1003 394 -371 -648 -343 149 390 258 -36 -215 -171 -11 105 99 21 -45 -49 -17 17 18 12 -9 </filter> <adc-profile num=16> 922 550 201 98 1280 112 1505 53 864 14 533 40 48 26 15 197 </adc-profile> </sniffer> <tx> <dacDiv=2.5> <txFirInterpolation=1> <thb1Interpolation=2> <thb2Interpolation=2> <txInputHbInterpolation=1> <iqRate_kHz=80000> <primarySigBandwidth_Hz=20000000> <rfBandwidth_Hz=40000000> <txDac3dBCorner_kHz=92000> <txBbf3dBCorner_kHz=20000> <filter FIR gain=6 num=16> 26 -292 -75 333 339 -659 -2192 21034 -2192 -659 339 333 -75 -292 26 0 </filter> </tx> </profile>
3.The main issue addressed by outlined work around:
3.1. Even with correct modification to Linux Device Tree, initial initialization of AD9371 at boot up is failing due to a time out of driver waiting for calibration routine execution in AD9371 firmware.
[ 3.560034] random: crng init done
[ 84.532030] ERROR: 283: MYKONOS_waitInitCals() returned an ARM error
[ 84.557234] ERROR: 258: Device not in radioOff/IDLE state. Error in MYKONOS_enableTrackingCals()
[ 84.591936] ERROR: 364: MYKONOS_waitArmCmdStatus() exited due to ARM error for the desired ARM opcode
[ 84.601111] ERROR: 145: ARM command to move to radioOn state failed.
[ 84.608698] ERROR: 364: MYKONOS_waitArmCmdStatus() exited due to ARM error for the desired ARM opcode
[ 84.617880] ERROR: 257: ARM Command Error in MYKONOS_setObsRxPathSource()
3.2. It was discovered that if TX_QEC_INIT calibration flag is disabled, Driver is not failing anymore. TX is operate fine after that but RX still not working.
% Dis TX_QEC_INIT Calibration using command line
cd /sys/kernel/debug/iio/iio:device1
echo 31231 > /sys/kernel/debug/iio/iio:device1/adi,default-initial-calibrations-mask
echo 1 > /sys/kernel/debug/iio/iio:device1/initialize
3.3. It was discovered that the profile, exactly the same as AD9371 configuration in Linux Device Tree has to be reload as the net step to make RX chain working (the MATLAB script is used).
h = intelsoc;
ProfileFile = 'ad9371_80MHz_profileMTG.txt';
h.putFile(ProfileFile,'/tmp') % FTP the configuration file over
ProfileConfigLocation = h.system('ls /sys/bus/iio/devices/iio:device*/*profile_config*');
ProfileConfigWrite = sprintf('cat /tmp/%s > %s',ProfileFile,ProfileConfigLocation);
msg = h.system(ProfileConfigWrite);
