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AFE7950: how to read fref status and produce test pattern

Part Number: AFE7950

Hi,

The reference clock for afe7950 is fed from lmx2694 directly and clock reate is 11520MHz. 

I am trying to product constant test patten by using dacJesdConstantTestPatternValue function, but no signal.

I initialized afe by log file of Latte and jesd_fs_state value was read as 00, its expected value is 0x55.

1> When JESD RX states is not established, is not test pattern produced?

2> How can I check whether input reference clock is healthy or not?

There was no initial errors at early stage of test. The board seems to be worse as test goes on. 

Anyhow 11520MHz clock from lmx2694 is recognized by spectrum analyzer.

3> the function dacJesdConstantTestPatternValue is a little bit different from Latte log.

When I select A, the registers Latte wrote are 0xb8 ~ 0xbb, but C function wrote 0xb8~0xbf.

4> Was the function checkDeviceHealth verified?

It looks like operating differently than comments.

5> C library verstion

I downloaded C_libraries_CAFE2p5.zip but zipped folder name was CAFE2p0. I need to check if I downloaded right file.

Regards,

YS

  • Hi YS,

    1. Even if the JESD link is not established the test pattern, dacJesdConstantTestPatternValue, should still work. Is this being tested on the AFE7950EVM? One thing to check is that the script is setup to use external clocking and if the EVM is being used then it should be modified for external clocking.

    2. The way to check is to use the test pattern that you mention in your first question. 

    Our team is looking into your last two questions and we should have an answer by the beginning of next week. 

    Regards,

    David Chaparro

  • Hi Yoonsun,

    3) When you are using both commands are you setting the same value for I and Q? This register holds the LSBs of the I value given in the function. 

    (dacJesdConstantTestPatternValue(Enable,Channel,Band,I Value, Q Value))

    4) This function was verified. Can you share the differences that you are noticing?

    5) The latest files are the ones available in the secure folder. 

    Regards,

    David Chaparro

  • Hi David,

    The comments about healthOk in the checkMcuHealth(afeId, &mcuHealth) function says that this value is 1 if the MCU is working properly and 0 if MCU is stuck.

    However in the checkDeviceHealth function, it prints "MCU Okay" when mcuHealth is 0.

    Regards,

    YS

  • Hi Yoonsun,

    After checking with our software team we have found that we have an updated CAFE library that has not been released yet and the issue that you noticed, checkDeviceHealth, was fixed. We are working on getting the updated library and its supporting documentation. Once we have this we will post it on the AFE79xx secure folder. 

    Regards,

    David Chaparro