Lpc2000

Hi Ezequiel,

you find the formulas in the User Manual (Chapter 15,
Reference clock divider).

For a 60 MHz PCLK you obtain:

RTC_PREINT = int( 60e6/32768 ) - 1 = 1830
RTC_PREFRAC = 60e6 - ((1830 + 1) * 32768) = 1792

For the widely used 14.7456 MHz crystal, where you can
set CCLK and PCLK to 58.9824 MHz, you obtain
RTC_PREINT=1799, RTC_PREFRAC=0

Cheers,
Rolf


--- acetoel <acetoel@...> wrote:

> 
> Ups... I didn't do that... how can I set it up, if I
> have a PCLK and
> CCLK of 60Mhz?
> Thanks
> Ezequiel
> 
> --- In lpc2000@yahoogroups.com, "lpc_bavaria"
> <lpc_bavaria@y...> wrote:
> > 
> > Hi Ezequiel,
> > 
> > have you set the prescaler registers RTC_PREINT
> and RTC_PREFRAC to
> > divide down your pclk to 32.768 kHz?
> > 
> > Cheers,
> > Rolf
> > 
> > 
> > --- In lpc2000@yahoogroups.com, "acetoel"
> <acetoel@y...> wrote:
> > > 
> > > Hello, I have set up the RTC and make a simple
> program to test it. But
> > > it doesn't work! Here is the code... on the PC
> (connected to the
> > > serial port) I always view the same time 19:8:51
> > > Thanks
> > > Ezequiel
> > > 
> > > #include "LPC210x.h"
> > > #include "Init.h"	
> > > #include "UART.h"
> > > #include "Delayus.h"
> > > 
> > > #define  Boton 0x80000000
> > > #define  LED1  0x10000000
> > > #define  LED2  0x20000000
> > > #define  LED3  0x40000000
> > > 
> > > UInt8  contador;
> > > UInt16 Counter2;
> > > UInt32 Hour,Min,Sec;
> > > 
> > > 
> > > int main (void) 
> > > {	
> > > 	/*Initialize the system*/
> > >  InitLPC2106();
> > >  InitCom();		//115200 bauds
> > >  IODIR=0x70000000;
> > >  IOCLR=0x70000000;
> > > 	
> > >  RTC_CCR=0;
> > >  RTC_CIIR=0x00000000;
> > >  RTC_AMR=0x00000000;
> > >  //real date time setting
> > >  RTC_SEC=0x00000033;
> > >  RTC_MIN=0x00000008;
> > >  RTC_HOUR=0x00000013;
> > >  RTC_DOM=0x00000006;
> > >  RTC_DOW=0x00000004;
> > >  RTC_DOY=0x00000004;
> > >  RTC_MONTH=0x00000001;
> > >  RTC_YEAR=0x000007D5;
> > >  //alarm setting
> > >  RTC_ALSEC=0x00000001;
> > >  RTC_ALMIN=0x00000001;
> > >  RTC_ALHOUR=0x00000001;
> > >  RTC_ALDOM=0x00000001;
> > >  RTC_ALDOW=0x00000001;
> > >  RTC_ALDOY=0x00000001;
> > >  RTC_ALMON=0x00000001;
> > >  RTC_ALYEAR=0x000007D0;
> > >  //start rtc
> > >  RTC_CCR=0x00000001;
> > > 	
> > > 	contador=0x00;
> > > 	IOSET = LED2;
> > > 	IOSET = LED3;
> > > 	printf ("Ezequiel L. Acetp %c%c",'\n','\r');
> > > 	//printf("Ezequiel L. Aceto\n");
> > > 	//printf("Sunixs Microsystems\n");
> > > 	while(1)
> > > 	{
> > > 	  IOSET = LED1;
> > > 	  delayus(1000); //0.5 Sec delay
> > > 	  IOCLR = LED1;
> > > 	  delayus(1000);
> > > 	  Hour = RTC_HOUR;
> > > 	  Min  = RTC_MIN;
> > > 	  Sec  = RTC_SEC;
> > > 	  printf("%2d : %2d : %2d  ",Hour, Min,
> Sec,'\n','\r');
> > > 	  Hour = 0x00;
> > > 	  Min  = 0x00;
> > > 	  Sec  = 0x00;
> > > 	}
> > > }
> 
> 
> 
> 


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