see http://mbed.org/users/no2chem/notebook/mbed-clock-control--benchmarks/

Dependencies:   mbed

ClockControl/ClockControl.cpp

Committer:
no2chem
Date:
2010-01-24
Revision:
0:b5d3bd64d2dc

File content as of revision 0:b5d3bd64d2dc:

#include "ClockControl.h"

void setPLL0Frequency(unsigned char clkSrc, unsigned short M, unsigned char N)
{
      LPC_SC->CLKSRCSEL = clkSrc;
      LPC_SC->PLL0CFG   = (((unsigned int)N-1) << 16) | M-1;
      LPC_SC->PLL0CON   = 0x01;             
      LPC_SC->PLL0FEED  = 0xAA;
      LPC_SC->PLL0FEED  = 0x55;
      while (!(LPC_SC->PLL0STAT & (1<<26)));
    
      LPC_SC->PLL0CON   = 0x03;
      LPC_SC->PLL0FEED  = 0xAA;
      LPC_SC->PLL0FEED  = 0x55;
}

void setPLL1Frequency(unsigned char clkSrc, unsigned short M, unsigned char N)
{
      LPC_SC->CLKSRCSEL = clkSrc;
      LPC_SC->PLL1CFG   = (((unsigned int)N-1) << 16) | M-1;
      LPC_SC->PLL1CON   = 0x01;             
      LPC_SC->PLL1FEED  = 0xAA;
      LPC_SC->PLL1FEED  = 0x55;
      while (!(LPC_SC->PLL1STAT & (1<<26)));
    
      LPC_SC->PLL1CON   = 0x03;
      LPC_SC->PLL1FEED  = 0xAA;
      LPC_SC->PLL1FEED  = 0x55;
}

unsigned int setSystemFrequency(unsigned char clkDivider, unsigned char clkSrc, unsigned short M, unsigned char N)
{
    setPLL0Frequency(clkSrc, M, N);
    LPC_SC->CCLKCFG = clkDivider - 1;
    SystemCoreClockUpdate();
    return SystemCoreClock;
}