PLL

Published 29 Nov 2009, by Simon Ford

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Show/hide line numbers main.cpp Source File

main.cpp

00001 #include "mbed.h"
00002 
00003 int main() {
00004     int Fin = 12000000; // 12MHz XTAL
00005     
00006     printf("PLL Registers:\n");
00007     printf(" - PLL0CFG = 0x%08X\n", LPC_SC->PLL0CFG);
00008     printf(" - CLKCFG  = 0x%08X\n", LPC_SC->CCLKCFG);
00009     
00010     int M = (LPC_SC->PLL0CFG & 0xFFFF) + 1;
00011     int N = (LPC_SC->PLL0CFG >> 16) + 1;
00012     int CCLKDIV = LPC_SC->CCLKCFG + 1;
00013 
00014     printf("Clock Variables:\n");
00015     printf(" - Fin = %d\n", Fin);
00016     printf(" - M   = %d\n", M);
00017     printf(" - N   = %d\n", N);
00018     printf(" - CCLKDIV = %d\n", CCLKDIV);
00019 
00020     int Fcco = (2 * M * 12000000) / N;
00021     int CCLK = Fcco / CCLKDIV;
00022 
00023     printf("Clock Results:\n");    
00024     printf(" - Fcco = %d\n", Fcco);
00025     printf(" - CCLK = %d\n", CCLK);    
00026 }