AFE7444EVM: DACs output issue

Prodigy 165 points

Replies: 5

Views: 48

Part Number: AFE7444EVM

Hi, I continue struggling with AFE7444. So far I have new 2 problems.

Conditions: using AFE744EVM connected to Enclustra Mercury PE1 Base board with XU7 Module (XCZU15EG-2FFVC900I)

AFE is set to standard mode 6 (300 MHz). The firmware for FPGA is based on your official example "KCU105AFE74xx".

1) The first problem: when I try synchronize JESD for all DACs (A+B+C+D) to transmit some signal, meanwhile all ADC's JESD are also synchronized, the output signals of all DACs have horrible impulse noise. Alarm JESD for TX part also shows errors, so it seems like this noise is caused by the loss of the transmitted data. But when I turn off the ADCs JESD - the signals of all DACs become clean and all the errors are gone. Also if make sync of JESD only for DAC A+B+C - the signal is clean on these outputs, but of course there is no signal on DAC D.

     

2) In this topic: https://e2e.ti.com/support/rf-microwave/f/220/p/849298/3157633#3157633  I posted the solution: how to generate the config sequence to use it in the future to work with micro-controller for example. I used software ver. 2.2.1. Now I found on your web site newer version: 2.2.7. I installed it and my approach doesn't work! When I activate Dump Mode ON for PG3.0 the logFile.txt is not updated when I go though my algorithm. So, what's now? How to get the right sequence to work with your chip for the real design??? 

5 Replies

  • Guru 57595 points

    Nihal,

    We are looking into this.

    Regards,

    Jim

  • In reply to jim s:

    Regarding my 2nd question:

    I found that NEW location for the logFile is: C:\Users\Public\Documents\Texas Instruments\AFE74xx\Log Files

    But still the generated cfg file in this folder doesn't work when I use it at Low Level View tab, cause programming of AFE is quite interactive: sometimes you should read and only after that write the right value.

    Could you please explain, how to get, how to save a working sequence of commands, at least a python script that could be used further as an algorithm for starting up AFE connected through spi to micro-controller? Even in your datasheet you ask to use your GUI to get the working sequence cause the process of startup is really complicated. 

    Do you also know, that lots of thing in your GUI doesn't work? For example update buttons don't work in Cross-bar, SERDE Lane ON/OFF, RX and TX sections and etc, It's easier to say which buttons work rather than count what is not working.

    1st question is still open too.

  • In reply to Nihal Ummer:

    Hey NIhal, 

    Regarding the spurs you see on TX output. Can you see if programming sysref to pulse mode makes a difference in the spectrum? Reference image  below. 

    You say that the dump files found in the public documents folder doesnt work when attempting to load it through low-level.Try loading a config file that you've verified to work, one that you generated from the older version of the GUI. Load that config file into the new version of the GUI. Does that work?

    Regarding python script you can find helpful documents on how to use python to program the AFE in the following path. 

    C:\Program Files (x86)\Texas Instruments\AFE74xx\Python Scripts\Help Documents

    Certain functions such as the crossbar config in the GUI require that you set and update the desired parameters before programming the device.

    Yusuf 

  • In reply to Yusuf%20Agoro:

    Hi, Yusuf. Thank you for your answer. 

    Previously I've already checked it without continuous sysref and it does't affect. The only thing which affects so far it's when I turn off the sync with ADC's JESD, when it's turned of - the output is good.

    Regarding config files. When the board is connected I set settings according to Mode6 and after that go though Init Script, Get Rx/Tx.., LMK Config and Run Complete Startup by the end of action ADC and DAC are working with the problems i mentioned above. But when I use cfg file ( which was made with the same settings mode 6 but with activated Dump Mode PG3.0, so through the log files ) only ADC part is working, there is no output on DAC A,B,C though there are no jesd alarms, only on D, but it is initial problem.

    This behavior is not connected with the version of GUI, the thing is that previously I checked those cfg files during loopback mode inside the chip and it was working, but now I have real input and output like in the reference design "KCU105AFE74xx".

  • In reply to Nihal Ummer:

    Nihal, 

    please send me the .cfg script you are using, along with a snapshot of the Advanced, AFE74xx RX and AFE74xx TX pages in the GUI. 

    Yusuf