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TMS320F280025C: F280025PTS LQFP48

Danny Chan
Intellectual 600 points

Part Number: TMS320F280025C
Other Parts Discussed in Thread: SYSCONFIG

Hi,

I would like to F280025PTS LQFP48 for motor application, now I need ONE more GPIO as external interrupt signal, I understand both X1 and X2 can be used for GPIO if use Internal clock instead of external, my question is if I use internal clock what's the consequence or disadvantage for precise timing application such as motor / pwm !

Danny

  • 0
    TI__Genius 11076 points

    Hello Danny,

    Refer to section 7.11.3.2 Clock Frequencies, Requirements, and Characteristics of the F280025C device datasheet for the internal clock specifications. Also note in particular the clocking alternative listed in Figure 7-12, requiring only X1, not X2.

    Alternatively- and I think you'll find this option quite helpful- refer to the sections on the AIO pins.

    • 6.4.2 Digital Inputs on ADC Pins (AIOs) defines AIO. They are input-only digital pins muxed with analog pins. These inputs can be programmed to act as an input to anything a regular GPIO can be an input to, if I recall correctly.
    • Table 7-7. Analog Pins and Internal Connections defines which analog pins are AIOs.
      • A1 is muxed with AIO232
      • A4/C14 is muxed with AIO225
      • A10/C10 is muxed with AIO230

    Regards,
    Jason Osborn

  • 0 in reply to Jason Osborn
    Intellectual 600 points

    Hi Jason,

    Thanks for your information, I will stay on X1 and X2 for external clock approach and use A4 as GPIO.

    Can you let me know how to configure AIO as GPIO according to Table 6.6, what's AMSEL option ? any Drivelib example ?  

    Note

    The analog pins that contain AIOs are in analog mode by default. AIO mode is enabled by configuring the AMSEL option of GPIOH for the analog pin. In addition, if using the HIC mux options on the AIO pins, an external pullup is required.

    Danny

  • +1 in reply to Danny Chan
    TI__Genius 11076 points

    Danny,

    Take a look at driverlib GPIO example 4, gpio_ex4_aio_external_interrupt- by the name, that seems perfect for your application. Refer to gpio_ex4_aio_external_interrupt.c lines 153 to 165 for only the relevant pin configuration.

    Please note that while this example does not use the SysConfig tool, the SysConfig section System->AIO provides a very intuitive and easy to configure interface for performing these configurations.

    Regards,
    Jason Osborn

    EDIT: Just as a note I forgot to address, AMSEL refers to one of the GPIO configuration registers. Specifically, GPIO_CTRL_REGS -> GPyAMSEL.GPIOx controls the gpio configuration register for GPIO subset y. For the F28002x, I believe this is only GPIO subset H. Driverlib handles most of the GPIO configuration for you, especially when using SysConfig, so it is rare that you'll specifically need this information.