bsp.h File Reference

Low level hardware functions for the MOD5441x platform. More...

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Functions
void	SpreadSpectrumOscillator (bool enable)
	Enable spread spectrum oscialltor mode on the CPU clock.

Detailed Description

Low level hardware functions for the MOD5441x platform.

Function Documentation

SpreadSpectrumOscillator()

void SpreadSpectrumOscillator

(

bool

enable

)

Enable spread spectrum oscialltor mode on the CPU clock.

The 25MHz CPU oscillator defaults to standard mode, but can be put in a spread spectrum mode that will help with radiated emissions. This will reduce EMI, but will cause the clock to have some jitter.

When enabled, the oscillator center frequency is reduced by 2% to avoid overclocking the CPU. The frequency will then vary by +/- 2%. This means the average clock rate will be reduced by 1% when this feature is enabled. To compensate, the system CPU_CLOCK variable and system time tick rate aer modified to reflect the new bus clock speed. Finally, the console/debug serial port will be closed and reopened to recalculate the baud rate.

Warning

Any periperhals or clock dependent sections of your application must take this adjustment into consideration. We recommend calling this function in the very beginning of the application to avoid baud rate miscalculations.

Parameters

enable

Set to true to enable spread spectrum mode