Is it possible on the KL03 to drive the LPTimer at greater than 8 Mhz using the internal reference clock?

[chucksmith]

The datasheet says max LPTmr frequency is 24 Mhz. The reference guide says LPTmr can be driven from the "internal reference clock". The MCG_Lite can be configured for a 48 Mhz high frequency internal reference clock. But I don't see how to set the mcglite parameters to produce more than an 8 Mhz clock for the LPTmr. Currently I have:

    const mcglite_config_t mcgliteConfig = {
        .outSrc = kMCGLITE_ClkSrcHirc,
        .irclkEnableMode = kMCGLITE_IrclkEnable, 
        .ircs = kMCGLITE_Lirc8M,
        .fcrdiv = kMCGLITE_LircDivBy1,
        .lircDiv2 = kMCGLITE_LircDivBy1,
        .hircEnableInNotHircMode = true,
    };

When I call CLOCK_GetFreq(kCLOCK_McgInternalRefClk), I get 8 Mhz, which the LPTmr does seem to be clocking at.

Thanks,

Chuck

[chucksmith]

Thanks Pavel!

[pavel_krenek · Accepted solution]

Hi Chuck,

it is not possible to clock the LPTMR higher frequency than 8 MHz if you are using internal oscillator. Clock module MCG Lite does not include FLL part and 8 MHz is maximum possible for this peripheral. But as you mentioned  LPTMR can run on 24 MHz but with using external reference (OSCERCLK).

Best regards,

Pavel