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RTOS/TM4C1294NCPDT: TI-RTOS clock settings

Harshel
Intellectual 955 points
Part Number: TM4C1294NCPDT
Other Parts Discussed in Thread: EK-TM4C1294XL

Tool/software: TI-RTOS

Hi,

I am developing embedded application on TM4C1294NCPDT on TI-RTOS. I have EK-TM4C1294XL as well as custom board.

I need help for below:

1. I have to check CPU clock frequency on oscilloscope. How can I take out clock frequency on any GPIO pin?

2. I have to change crystal selection on from 16MHz to 25MHz and vice versa.

3. How to configure TI-RTOS clock settings?

  • 0
    Intellectual 955 points
    I am using TI-RTOS 2.16 and CCS v6.2
  • 0
    TI__Guru*** 128095 points
    Hello Harshal,

    There isn't a way to take the clock frequency out to a GPIO. Best way to check the frequency is set right is to do something like setup a timer to toggle a GPIO or output a PWM. If the clock is not set to what you expect, you'll notice a difference that way.

    The crystal change mainly means the SysCtlClockFreqSet API needs to be called with the right parameter, either SYSCTL_XTAL_25MHZ or SYSCTL_XTAL_16MHZ. I will need to loop in the RTOS team for them to comment on how to tweak that in TI-RTOS though.
  • 0 in reply to Ralph Jacobi
    TI__Mastermind 30830 points
    To switch to a 25MHz crystal try adding the following to your .cfg file

    var Boot = xdc.useModule('ti.catalog.arm.cortexm4.tiva.ce.Boot');
    Boot.xtal = Boot.XTAL_25MHZ;

    To set the CPU frequency:

    Boot.configureClock = true;
    Boot.cpuFrequency = xyz; /* xyz = your frequency in Hz */

    The Boot module will internally inform BIOS about the new CPU frequency.

    Alan