topic bandgap enable in Kinetis Microcontrollers

bandgap enable

Lupo — Fri, 12 Feb 2016 11:32:06 GMT

With ref to a mkl03z32 mcu, kds3.1 and ksdk1.3, when using the fsl_adc16 with the "Vref pair" as Voltage reference, the measure of the bandgap gives erratic measures...

It is so necessary to add the following code

PMC_REGSC |= PMC_REGSC_BGBE_MASK;

SIM_SCGC6 |= SIM_SCGC6_ADC0_MASK;

to make it operate.

Imho selecting the measure of the bandgap in the component should enable automatically the bandgap function, or at least show a warning!

Re: bandgap enable

isaacavila — Mon, 02 Nov 2020 13:28:52 GMT

Hello Michael,

The instruction SIM_SCGC6 |= SIM_SCGC6_ADC0_MASK; isn't necessary due it is already set in ADC16_DRV_Init function:

/* Enable clock for ADC. */
    CLOCK_SYS_EnableAdcClock(instance);

And for PMC_REGSC |= PMC_REGSC_BGBE_MASK, it is specified in Reference Manual's section 28.1.1 ADC0 connections/channel assignment a small note at the end of the table:

And when you specify A/D channel to be Bandgap (channel AD27) you only configure ADCH field for ADC0_SC1 register, so user should enable PMC bandgap independently because it is related to other module.

I hope this can help you!

Best Regards,

Isaac Avila

Re: bandgap enable

Lupo — Fri, 26 Feb 2016 13:17:37 GMT

Thanks Isaac, my problem is (was with ksdk v2) the too easy use of Processor Expert that often makes me forget about hw and manuals...