File content as of revision 17:927fc1eceb9d:

#include <time.h>
#include "peripherals.h"

int  RtcIsSet() { return !(LPC_RTC->RTC_AUX & 0x10); } //27.6.2.5 RTC Auxiliary control register - RTC Oscillator Fail detect flag

void RtcGetTm(struct tm* ptm)
{
    ptm->tm_sec    = LPC_RTC->SEC;
    ptm->tm_min    = LPC_RTC->MIN;
    ptm->tm_hour   = LPC_RTC->HOUR;
    ptm->tm_mday   = LPC_RTC->DOM;
    ptm->tm_mon    = LPC_RTC->MONTH - 1;
    ptm->tm_year   = LPC_RTC->YEAR  - 1900;
    ptm->tm_wday   = LPC_RTC->DOW;
    ptm->tm_yday   = LPC_RTC->DOY   - 1;
    ptm->tm_isdst  = -1; // -ve should signify that dst data is not available but it is used here to denote UTC
}
void RtcSetTm(struct tm* ptm)
{
    LPC_RTC->CCR     = 2;                   //Stop and reset the divider (CTCRST bit 1 = 1)
    LPC_RTC->SEC     = ptm->tm_sec;         // 0 --> 59
    LPC_RTC->MIN     = ptm->tm_min;         // 0 --> 59
    LPC_RTC->HOUR    = ptm->tm_hour;        // 0 --> 23
    LPC_RTC->DOM     = ptm->tm_mday;        // 1 --> 31
    LPC_RTC->MONTH   = ptm->tm_mon  + 1;    // rtc    1 -->   12; tm 0 -->  11
    LPC_RTC->YEAR    = ptm->tm_year + 1900; // rtc 1900 --> 2100; tm 0 --> 200
    LPC_RTC->DOW     = ptm->tm_wday;        // 0 --> 6 where 0 == Sunday
    LPC_RTC->DOY     = ptm->tm_yday + 1;    // rtc 1 --> 366;     tm 0 --> 365 
    LPC_RTC->RTC_AUX = 0x10;                //27.6.2.5 RTC Auxiliary control register - RTC Oscillator Fail detect flag - Writing a 1 to this bit clears the flag.
    LPC_RTC->CCR     = 1;                   //Release the divider (CTCRST bit 1 = 0)
}
void RtcInit()
{
    LPC_RTC->CCR       =    1;    //27.6.2.2 Clock Control Register - enable the time counters (CLKEN bit 0 = 1); no reset (CTCRST bit 1 = 0); enable calibration counter (CCALEN bit 4 = 0)
    LPC_RTC->CIIR      =    0;    //27.6.2.3 Counter Increment Interrupt Register - set to not interrupt
    LPC_RTC->AMR       = 0xFF;    //27.6.2.4 Alarm Mask Register - mask all alarms
    LPC_RTC->RTC_AUXEN =    0;    //27.6.2.6 RTC Auxiliary Enable register - mask the oscillator stopped interrupt
    LPC_RTC->ILR       =    3;    //27.6.2.1 Interrupt Location Register - Clear all interrupts

}