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    User name R. Michaels

    Log entry time 16:39:36 on October 09, 2009

    Entry number 294033

    keyword=ADC18 test crate: important bug fix (fixes oversampling)

    Thanks to Dave Abbott and Ed Jastrzembski of the DAQ group, a
    simple bug was found in adc18_reset which caused the "buffer full"
    bit to remain stuck with the "new" ADC18 software. Instead of
    writing to "csr" the code wrote to "ctrl" -- a mistake.
    The bug was found by reproducing the symptoms in the test crate
    and showing the details to Dave and Ed.

    Reminder: about 6 weeks ago we made improvements to our ADC18
    library which dealt more correctly with the state machine logic,
    leading to the "new" ADC18 software. However, this had a fault
    that when the DAQ crashed the "buffer full" condition remained on,
    which could lead to corrupted data. We sadly had to roll back our
    old code, which mostly works (we've been taking data for weeks with
    little complaint) -- but not with oversampling.

    Now that we have this fix we can try oversampling with beam and our
    full system -- perhaps next week ? The new code should make overs-
    ampling work and should have zero "bad1" data or glitches. I hope.

    At the moment, the test crate has 5 ADC18 which work well with
    oversampling.


    A copy of this log entry has been emailed to: mercado,paschke,rom,kkumar