Front GPIO output pulse width issue

  • Hi there


    I used the oscilloscope to get the waveform of the GPO output.

    I found that the output waveform is different from the manual description.

    About the test design please reference mE5MA_VCX-QP_IO_Test.va.


    Environment

    Platform : mE5MA VCX-QP (Front GPO)

    Physical Properties of Trigger Signals Setting

    00.PNG


    Sample rate : 16 MHz


    ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------


    Test 1


    [Channel 0]

    Process0/SelectSource_0/Select = 0

    Source properties :

    Downscale Downscale = 1

    Downscale SelectedPulse = 1

    signalWidth = 6250 tick * 8 ns (1/125 MHz) = 50 us

    signalDelay= 1050 * 8 ns (1/125 MHz) = 8.4 us


    [Channel 1]

    Process0/SelectSource_1/Select = 2

    Source properties :

    Downscale Downscale = 2

    Downscale SelectedPulse = 2

    signalWidth = 5000 tick * 8 ns (1/125 MHz) = 40 us

    signalDelay = 0 * 8 ns (1/125 MHz) = 0 us



    Output


    [Channel 0]


    signal width = 62.25 us or 63.44 us

    01.PNG


    delay = 8.374 us

    01-1.PNG


    When set the Process0/ExSync/Exposure/Delay/delay = 0.

    01-2.PNG


    And I reference the Operator SignalDelay.

    Delay Timing diagram .PNG


    The delay signal should be negative. Why was the delay signal be positive?

    And the signal width = 62.25 us or 63.44 us. Is this a phenomenon caused by physical circuits?


    ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------


    Test 2


    [Channel 0]

    Process0/SelectSource_0/Select = 1

    Source properties :

    Downscale Downscale = 2

    Downscale SelectedPulse = 1

    signalWidth = 5000 tick * 8 ns (1/125 MHz) = 40 us

    signalDdelay = 0 * 8ns (1/125MHz) = 0 us


    [Channel 1]

    Process0/SelectSource_1/Select = 2

    Source properties :

    Downscale Downscale = 2

    Downscale SelectedPulse = 2

    signalWidth = 5000 tick * 8 ns (1/125 MHz) = 40 us

    signalDdelay = 0 * 8ns (1/125MHz) = 0 us


    Output


    02.PNG


    And I reference the Operator Downscale

    Downscale Timing diagram .PNG


    Why did there appear pulses with a width about 6 us?


    Thank you.


    Jesse

  • Hi Jesse,


    As soon as I have some time for investigating this I will do this.

    Feel free to contact our support team as a second option.

    I am really sorry, but right now I have no clear answer.

    Björn RuddeMicroSiSo.png
    Senior Technical Sales and
    Field Application Engineer

    please:thumbup: