This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Inputs are broadcast to all multiplexed functions

Part Number: TMS570LC4357

Figure 6-3 of the TMS570LC4357 Technical Reference Manual (SPNU563A) shows an example of how inputs on a terminal are broadcast to all connected multiplexed functions. Is it possible for the settings of some of those functions to affect the input signal as seen by other functions?

For example, terminal W10 is multiplexed to GIOB[3] and DCAN4RX. If the intended use of the terminal is as DCAN4RX, are there recommended settings for GIOB[3] regarding direction, pull up, etc?

  • The W10 pin is connected as input to both the GIOB[3] and DCAN4RX. there is no input multiplexing on this pin. It is fine if GIOB[3] is not used. If you want to use GIOB[3] as input, you can select R4 pin to be used as GIOB[3] (input only). 

  • Hi, thanks for the response.

    I would like to use pin W10 as DCAN4RX, with GIOB[3] not used.

    By default if not otherwise configured, GIOB[3] in the GIO module will be an input with internal pull down enabled.

    Because W10 does not have internal multiplexing, would the default internal pull down from the GIO module effectively be an internal pull down on DCAN4RX as well?

  • The internal pull up and down is very weak. The internal pull-down from GIO module doesn't affect CAN4's bus status. 

    As stated in the notes, it's better to configure the GIOB[3] as output pin.