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TMS320F28388D: Using a single-ended 3.3V level clcok

ROMAIN LIEVRE
Prodigy 10 points
Part Number: TMS320F28388D
Other Parts Discussed in Thread: C2000WARE

Hi everyone,

I would like to use a single-ended 3.3V levle clock on pin X1.

In the datasheet i see this sentence: "Crystal oscillator input or single-ended clock input. The device initialization software must configure this pin before the crystal oscillator is enabled. To use this oscillator, a quartz crystal circuit must be connected to X1 and X2. This pin can also be used to feed a single-ended 3.3-V level clock." but there is no other information on the datasheet or on the TRM.

I don't understand if it's necessary to start the singled-ended clock after software initiliazation, or anithing else. Indeed generaly we want a stable clock before the POR.

Regards

  • 0
    TI__Mastermind 45606 points

    Hi Romain,

    I believe all of our F2838x software examples in C2000WARE configure the device to use a single-ended clock source, since our F2838x ControlCard uses a single-ended oscillator. You can take a look at the Device_init() function call in any SW example for further details.

    Relevant code within the function below:

        //
    // Set up PLL control and clock dividers
    //
    SysCtl_setClock(DEVICE_SETCLOCK_CFG);
    
    //
    // Define to pass to SysCtl_setClock(). Will configure the clock as follows:
    // PLLSYSCLK = 25MHz (XTAL_OSC) * 32 (IMULT) / (2 (REFDIV) * 2 (ODIV) * 1(SYSDIV))
    //
    #define DEVICE_SETCLOCK_CFG          (SYSCTL_OSCSRC_XTAL | SYSCTL_IMULT(32) | \
                                          SYSCTL_REFDIV(2) | SYSCTL_ODIV(2) | \
                                          SYSCTL_SYSDIV(1) | SYSCTL_PLL_ENABLE | \
                                          SYSCTL_DCC_BASE_1)

    Best,

    Kevin