hardware_pll

Functions

void pll_init (PLL pll, uint ref_div, uint vco_freq, uint post_div1, uint post_div2)
 Initialise specified PLL. More...
 
void pll_deinit (PLL pll)
 Release/uninitialise specified PLL. More...
 

Detailed Description

Phase Locked Loop control APIs

There are two PLLs in RP2040. They are:

For details on how the PLL's are calculated, please refer to the RP2040 datasheet.

Function Documentation

◆ pll_deinit()

void pll_deinit ( PLL  pll)

Release/uninitialise specified PLL.

This will turn off the power to the specified PLL. Note this function does not currently check if the PLL is in use before powering it off so should be used with care.

Parameters
pllpll_sys or pll_usb

◆ pll_init()

void pll_init ( PLL  pll,
uint  ref_div,
uint  vco_freq,
uint  post_div1,
uint  post_div2 
)

Initialise specified PLL.

Parameters
pllpll_sys or pll_usb
ref_divInput clock divider.
vco_freqRequested output from the VCO (voltage controlled oscillator)
post_div1Post Divider 1 - range 1-7. Must be >= post_div2
post_div2Post Divider 2 - range 1-7