NetDCU8 - Parallel port electrical configuration

    Hello,


    When I configured the parallel port to 5V (Jumper R33), what are the voltage level of the pins RD, NCS, NIRQ and NRES?


    With R33 resistor connected (5V configuration), I observed (without any device connected) that in pin D0-D7 and NIRQ gives 5V, but in the rest (RD, NCS, NRES) the voltage is 3,3V.


    What are the work voltages?


    Another thing is, that in the manual says that the default configuration is set to 3,3V, but until now we received all NetDCU8’s with this set to 5V. (We purchased 4 NetDCU8s).


    Best Regards,


    Jose MATA
    IFR Automotive

    The 5V setting is a little bit confusing, not to say unnecessary. The difference is that the pull-up resistors are pulling to 3.3 or to 5 V. But the diver chips remain 3.3V with 5V tolerant inputs. What does this mean in 5V mode?


    1. A signal, that is actively driven low by the NetDCU is 0V.
    2. A signal, that is actively driven high by the NetDCU is 3.3V.
    3. A signal, that is not actively driven by the NetDCU is pulled high to 5V.
    4. Any high signal driven by the periphery is accepted as 3.3V or 5V.


    Regards,


    H. Keller

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.