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Confused on F28027 AIOMUX setup

TobyM
Genius 5200 points
Other Parts Discussed in Thread: TMS320F28027

Hi Folks

I have some confusion with setting up the AIO pins as per the SPRUFN3C control and interrupts guide...

Looking at the DSP2802x_gpio.h file included with the example projects, I see I should be able to set the AIO Mux as so:

GpioCtrlRegs.AIOMUX1.bit.AIO2 = 2;   // AIO2 = A2 analog IN

However, looking at the table SPRUFN3C, Im not sure how to manage this for some of the other ADC's, say AIO1 = analog IN

Should it be: GpioCtrlRegs.AIOMUX1.bit.AIO1 = 1; ??

Its more the "AIO1" bit that Im puzzled over her, as AIO1 is not mentioned in the gpio.h...??

Thanks for any help, it would be much appreciated!

  • 0
    TI__Guru 64470 points

    I would also suggest looking at the datasheet for the TMS320F28027.

    You will see that the pins which include analog inputs that also can be configured as digital I/O, are the ones with the bitfield in the AIOMUX1 register.

    Specifically look in Table 2-2 to see the correlation.

    Those analog inputs that are dedicated pins, do not have a corresponding bit field to configure the mux, because there is no mux.

  • 0 in reply to BrandonAzbell
    Genius 5200 points

    To clarify, you mean there is no mux, thus no mux setting needed, because ADC gtoup A channel 1 is on a dedicated pin...?

    Many Thanks

  • 0 in reply to TobyM
    TI__Guru 64470 points

    I will attempt to clarify.  For the below description, I am using 2 documents.  The TMS320F28027 datasheet and the TMS320x2802x/TMS320F2802xx Piccolo System Control and Interrupts Reference Guide.  In the datasheet, I am referencing Table 2-2 in the ADC, Comparator and Analog I/O section.  In the above reference guide, please refer to Table 59, Figure 54 and Table 63.

    The following pins are dedicated analog inputs and have no alternate functionality such as I/O capability.  Therefore, no bits are defined in the AIOMUX1 to configure the alternate functionality.

    ADCINA7, ADCINA3, ADCINA1, ADCINA0, ADCINB7, ADCINB3, ADCINB1

     

    The following pins have alternate functionality, such as I/O, and therefore have associated bit fields defined in the AIOMUX1 to enable the alternate functionality.

    ADCINA6 (AIO6), ADCINA4 (AIO4), ADCINA2 (AIO2), ADCINB6 (AIO14), ADCINB4 (AIO12), ADCINB2 (AIO10)

  • 0 in reply to BrandonAzbell
    Genius 5200 points

    Ok I think Im understanding a bit better now.

    However looking at the example project, continuous ADC, which uses some of each of the mux'ed and non-mux'ed pins, I cannot see where the AIOMUX settings are made... whereas the GPIO settings used, are obvious in the ContinuousADC_DevInitF2802x.c file. I would have thought the AIOMUX settings would be handled in the same way/location?

    Or does setting the peripheral settings for use in itself setup AIOMUX settings by default??

    Thanks for bearing with me! :)