Changing Rtcs1-0; Real-Time Clock Interrupt/Wake Up; Reset Sources Affecting The Real-Time Clock - Philips P89LPC906 User Manual

Philips Semiconductors
REAL-TIME CLOCK/SYSTEM TIMER
FOSC2 FOSC1
(UCFG1.2) (UCFG1.1)
1 0
1 0
1 1
1 1

CHANGING RTCS1-0

RTCS1-0 cannot be changed if the RTC is currently enabled (RTCCON.0 =1). Setting RTCEN and updating RTCS1-0 may be
done in a single write to RTCCON. However, if RTCEN = 1, this bit must first be cleared before updating RTCS1-0

REAL-TIME CLOCK INTERRUPT/WAKE UP

If ERTC (RTCCON.1), EWDRT (IEN0.6) and EA (IEN0.7) are set to '1', RTCF can be used as an interrupt source. This interrupt
vector is shared with the watchdog timer. It can also be a source to wake up the device.

RESET SOURCES AFFECTING THE REAL-TIME CLOCK

Only power-on reset will reset the Real-time Clock and its associated SFRs to their default state.
2003 Dec 8
FOSC0
RTCS1:0
(UCFG1.0)
00
01
0
10
11
1
0 xx
1
CCLK Frequency
WDT Oscillator/DIVM
undefined
50
User's Manual - Preliminary -
P89LPC906/907/908
RTC Clock Frequency
undefined
WDT Oscillator/DIVM
(CCLK)