This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DAC38RF82EVM: TSW14J56 with DAC38J82 external trigger hardware modification

Part Number: DAC38RF82EVM
Other Parts Discussed in Thread: DAC38J82EVM, DAC38RF82, DAC38J82, ADC12DJ3200

Hi Hunsoo/ TI High Speed Data Converter Team,

A while back I asked a question about a one-shot trigger option for the DAC38RF82EVM, connected to the TSW14J56 pattern Generator card.  I was informed that the application team was looking into it, and someone would get back to me.  

Any progress on this issue?  If someone *did* respond to my initial query, all apologies...  but  I received no notification of their response.  I would have expected an answer to have been appended to the forum thread containing my original question.

Thanks,

-steve

  • Steve,

    The trigger function should work just the same as it does for the DAC38J82EVM. Is this related to triggering multiple EVM's with an odd octet setting?

    Regards,

    Jim 

  • Hi Jim,

    The odd octet setting was another issue, which contributed to instability/ poor repeatability of the trigger timing/ signal fidelity. Today I worked with the DAC38RF82EVM in 8-bit , single (real) channel mode with the DACclk set to 9 GHz. Our test pattern was sent "cleanly" every time, with minimal variation in the trigger latency (measured from falling edge of the trigger pulse (output on J12/'Trig Out C' port of the TSW14J56) and the leading edge of our signal).

    My question had to do with achieving a true "one-shot" type behavior with the DAC output pulse. Ken C wrote about using the preamble mode of the HSDC Pro Gui to effectively "loop" the trailing, zero-portion of the pattern file for generating a single signal pulse (defined in the preamble "window") in response to the user-invoked trigger (using the DAC38J82EVM). It didn't work for me: I get continuous looping of the pattern file, including the initial signal burst defined at the pattern file start (within the preamble window, for me 1024 samples).

    I'm not sure if I'm missing a setting in one of the GUIs (DAC or HSDCpro), or whether my DAC38RF82 EVM behaves a bit differently than the DAC38J82. It would be great to know whether a one-shot DAC output can be achieved with the 38RF82.

    Thanks as always,

    -steve
  • Steve,

    This from our software team:

    We do not have support for preamble in TSW14J56revD but we have support for Single Shot Generation(Generating and sending the tone to DAC only once. Tone will not be continuously played from the FPGA to DAC). Single Shot Generation was implemented in TSW14J56revB and is present in TSW14J56revD as well, though we haven’t tested this in recent times. You can try this out by adding the following parameter in the DAC INI file,

     

    Single Generation=1

    Regards,

    Jim

  • Hi Jim,

    I inserted the "Single Generation=1" line into the DAC .ini file, and it worked... but only for the default operating mode of HSDC Pro.

    I measured a single shot of our pattern file on the Ch.A DAC output, with the D2/Tx CLK LED blinking as usual. I observed this result using the (default) "Send" mode in the HSDC Pro GUI. When I enabled triggering in the HSDC Pro Gui, then the D2/Tx CLK LED stopped blinking.... and I wasn't able to measure any kind of output from the DAC. I tried triggering off both the DAC Ch.A output (nothing) and off the'Trig Out C' trigger signal (worked, but only captured the trigger pulse).

    If there's some way for the software team to achieve the same "Single Generation=1" behavior when using the Trigger capability of the HSDC Pro GUI, that would be fantastic. Our ideal scenario is to hardware trigger a one-shot DAC output... and then coordinate the data capture on the ADC12DJ3200 using this same hardware trigger.

    This is good progress. We seem to be *nearly* there, but I don't know what's involved to get the one-shot working with the trigger.

    Cheers & Thanks,
    -steve
  • Steve,
    Hopefully I will an answer for this by tomorrow.
    Regards,
    Jim
  • Steve,

    Can you answer these questions from our firmware team?

    1.       The trigger mode used by customer- Hardware, Software or SYSREF based trigger?

    2.       Is it possible to share the trigger process that customer is following?

    Correct process will be mentioned in the manual ‘High Speed Data Converter Pro.pdf’ available in the installed path of HSDC Pro

    C:\Program Files (x86)\Texas Instruments\High Speed Data Converter Pro

    Regards,

    Jim

  • Hi Jim,

    In order of preference, here's our near-term "wish list" for true one-shot triggering of the DAC:
    A) Hardware
    B) SYSREF (iff we have syncronization issues with A)
    C) Software

    In using the trigger function with the DAC38RF82EVM and the TSW14J56EVM, I follow the procedure outlined in the HSDC Pro GUI manual , and also deselect "Continous Triggering" in the DAC38RFxx GUI. I've successfully used the soft trigger (i.e. "Trigger" button click) function in the HSDC Pro in the past, validated by recording a single trigger pulse from the "Trig Out C" port of the TSW14J56 and our loaded (but looped) pattern file on the DAC output port ~ 120 ns later. When I put the "Single Generation =1" line into the DAC .ini file, then I don't observe anything on the DAC output... but the trigger pulse is still recorded on our scope.

    I hope this information helps your firmware team troubleshoot the problem.

    Thanks,
    -steve
  • Steve,

    They have found a problem with the firmware, but due to many other priorities, this may take a week or two before they can get around to working on this.

    Regards,

    Jim 

  • Steve,

    The firmware team gave me a new rbf file for you to try. You will also have to replace the lookup.csv file in the HSDC Pro directory. Both files can be downloaded from the link below. Let me know if you have any questions.

    Regards,

    Jim

     txn.box.com/.../c4u3exb028m9c3ss1kytdrk078441gat

  • Hi Jim,

    I tried both the .RBF (firmware) file and the .CSV (lookup) files you sent, and I did observe *something* on the output (Channel A) of the DAC...  but not what I was expecting/ wanted.  Here's a summary of what I observed:

    A)  A short glitch (~30 ns), appearing about ~ 290 ns or so after the leading edge of the trigger pulse.   The trigger-to-glitch latency varied a bit between separate HSDC Pro user sessions, but was very repeatable with a given HSDC Pro session.  The glitch seems like random garbage.

    B)  A longer output pulse ~ 14 us after the trigger, also bearing little resemblance to the expected signal pulse encoded by the loaded pattern file.  The duration of this  "consistent-but-wrong" output pulse matched that of the expected signal pulse, but with  much higher variability in the trigger-to-pulse latency than what I observed with the glitch.

    I reverted back to the original lookup .csv file, and still observed the same behaviour.  I rolled things back to the original configuration (maintaining the "SingleGeneration=1" line in the DAC38RF8x_LMF_811.ini file), and observed the expected/ desired "single shot" behavior from clicking the "Send" button in the HSDC Pro GUI.  As before, trying to use the Trigger in this original configuration only generates a trigger pulse, but no DAC output.

    I appreciate the firmware team's efforts to enable this function, and your patient help with this key issue.  Please let me know when they have an updated .RBF and/ or .CSV file to try, and I will test them.  

    Best Regards,

    -steve

  • Steve,

    This from the firmware team:

    The targ you are using is 811 mode of DAC38RF82 with DAC Sampling rate set as 9GSPS, correct?

     

    We missed to update ‘Interface name’ in Ini file and share it. It is attached to this post.

     

    As the Ini file was not updated, we can’t be sure the correct firmware was downloaded unless it is done through ‘Instrument Options-> Download Firmware’.

    Can we clarify the steps that customer followed to download the new firmware

     

    Correct Steps to be followed:

     

    • ·         Copy the .rbf file ‘TSW14J56REVD_TRIG_SINGLEGEN’ and place in the following path of installed location of HSDC Pro

    C:\Program Files (x86)\Texas Instruments\High Speed Data Converter Pro\14J56revD Details\Firmware

    • ·         Copy the .csv file ‘TSW14J56revD_IID_Lookup’ and replace with the existing one in the following path of HSDC Pro

    C:\Program Files (x86)\Texas Instruments\High Speed Data Converter Pro\14J56revD Details

    • ·         Copy the Ini file ‘DAC38RF8x_LMF_811_Singlegen’ and place it in the following path of HSDC Pro

    C:\Program Files (x86)\Texas Instruments\High Speed Data Converter Pro\14J56revD Details\DAC files

    • ·         Disconnect and connect to board in HSDC Pro GUI, the new ini file will be available in the Ini files drop down.

    Set DAC Sampling rate and choose the new Ini for all testing

     

    Please share with us the screenshots of DAC output. Can we also get the pattern file (output pulse) that is loaded in HSDC Pro? It will help to debug further."

    Regards,

    Jim

    DAC38RF8x_LMF_811_Singlegen.ini

  • Steve,

    I am going to close this post as we are talking via email.

    Regards,

    Jim