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CCS/TMS320F28335: QEPSTS[CDEF] IS ALWAYS ZERO,THIS BIT DOESN'T CHANGE

Victor123
Prodigy 210 points
Part Number: TMS320F28335

Tool/software: Code Composer Studio

If a direction change occurs between the unit position events, then
an error flag is set in the status register (QEPSTS[CDEF]).

But it doesn't change

  • 0
    TI__Mastermind 42756 points

    Hi Victor,

    Can you provide a snippet of your code for how you're testing this? Initialization and other relevant QEP code.

    How are you testing for the case where CDEF goes high? Has the QEPSTS.UPEVENT flag been set prior to a direction change occurring?

    I believe a direction change would have to happen between the UPEVNT pulses to trigger CDEF, like shown below:

    Best,

    Kevin

  • 0 in reply to Kevin Allen18
    Prodigy 210 points

        EQEP MODULE CONFIGURATION:

    I think there is something wrong with EQEP

    EQep1Regs.QDECCTL.bit.QSRC  = 0;            // QEP quadrature count mode
        EQep1Regs.QDECCTL.bit.QAP   = encABSwap;    //  1;
        EQep1Regs.QEPCTL.bit.PCRM   = 0;            // PCRM = 0 mode - QPOSCNT reset on index event
        EQep1Regs.QEPCTL.bit.QCLM   = 0;            // 0:Latch on position counter read by CPU. 1: Latch on unit time out
        EQep1Regs.QEPCTL.bit.IEL    = 3;            // Latches position counter on rising edge of the index signal
        EQep1Regs.QPOSMAX           = encResolution-1;
        EQep1Regs.QEPCTL.bit.QPEN   = 1;            // QEP enable
        EQep1Regs.QCAPCTL.bit.UPPS  = 0;            // 1/1 for unit position
        EQep1Regs.QCAPCTL.bit.CCPS  = 0;            // 1/2 for CAP clock
        EQep1Regs.QCAPCTL.bit.CEN   = 1;            // QEP Capture Enable

    Attached is data,Pls review.data.xlsx

  • 0 in reply to Victor123
    Prodigy 210 points

    Is there anyone can answer my issues?

  • 0 in reply to Victor123
    TI__Mastermind 42756 points

    Victor,

    I'm misunderstanding your question. Are you still wondering why QEPSTS[CDEF] is not getting set high?

    It doesn't seem like the register bit would be set based on what you've provided, i.e. doesn't seem like a direction change occurred in-between UPEVNTs.  Am I missing something?

    Best,

    Kevin

  • 0 in reply to Kevin Allen18
    TI__Mastermind 42756 points

    Hi Victor,

    Have you been able to resolve this issue on your own? Do you need any additional support?

    Best,

    Kevin