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Do I have bus contention if I see 2.4v on a signal that should be near 3.3V or ground?

Do I have bus contention if I see 2.4v on a signal that should be near 3.3V or ground?

  • Maybe not.  On some new SHARC products like ADSP-21467, there can be an unusual voltage on the signal pins with internal pullups.  If the pullup controls the voltage, it is 2.4V.  If a driver controls the voltage it is near 3.3V or near ground.  2.4V is a perfect logic high because Vih is 2.0V. It causes no error of any kind.
     
    During debug, it can look to the customer like bus contention.  When customers have circuit problems; they measure the voltage and see that 2.4V is not the 3 volts that they expected.  It may look as if there is something wrong with their circuit.  The 2.4V is normal, valid and expected for some processors.
  • This question has been closed by the EZ team and is assumed answered.