AnsweredAssumed Answered

i.MX6UL UART DCE/DTE mode refers

Question asked by Gerhard Laubscher on Aug 11, 2019
Latest reply on Aug 12, 2019 by igorpadykov

Good day,

i.M6UL refers -  (based on variscite SOM  Yocto build )

I recently discovered, on completion and now production of my hardware platform,

 that I have interpreted UART DCE/DTE Modes incorrectly -

Unfortunately the correct doc-info only came forward once we went into production with you,

making me aware of the following issue -

In my design, as seen from the processor, the following h/w pad/pin config has been wired -

RXD < in

TXD > out

RTS > out

CTS < in

Testing on h/w platform (DCE mode) the serial comms work with h/w flow OFF

 When enabled, no comms, since in DCE mode RTS dir = in,  CTS dir = out.


In DTE mode, RTS dir out, CTS dir in, but TXD = in,  RXD = out.

  This also presents a problem, since now there will be no serial comms,

   since txd/rxd dir is reversed, with reference to my h/w wiring-


What I would like to know, are there any additional register-set configuration

 to allow my h/w config to work, iow, to allow my particular h/w configuration to work,

or is the only option to scrap the production units, (clearly the last option)

  or to modify  > swop RTS/CTS signals with jumpers in DCE mode,

   or to swop  TXD/RXD in DTE with jumpers.


Thank you for your advice on this matter.



Gerhard Laubscher

Cape Town

South Africa