
Real time clock
UM0404
DocID13284 Rev 2
Figure 189. RTC block diagram
22.1 RTC
registers
22.1.1
RTCCON: RTC control register
The functions of the RTC are controlled by the RTCCON control register. If the RTOFF bit is
set, the RTC dividers and counters clock is disabled and registers can be written, when the
ST10 chip enters Power Down mode the clock oscillator will be switch off. The RTC has two
interrupt sources, one is triggered every basic clock period, the other one is the alarm.
RTCCON includes an interrupt request flag and an interrupt enable bit for each of them.
This register is read and written via the XBUS.
RTCCON (ED00h)
XBUS
Reset Value: 0x00h
Reset Value: 0000 000x 0000 0000b
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RTCPL
RTCPH
RTCDH
RTCDL
RTCAH
RTCAL
Main
Reload
=
programmable 20 bits divider
32 bits Counter
RTCCON
Alarm IT
Basic Clock IT
RTCAI
RTCSI
MUX
OSC_STOP
OSC32_STOP
32 kHz Oscillator
Clock Oscillator
Programmable Alarm register
Programmable Prescaler register
RTCH
RTCL
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-
-
-
-
-
-
OFF32
OSC
RTCOFF
-
-
-
RTCAEN
RTCAIR
RTCSEN
RTCSIR
RW
R
RW
RW
RW
RW
RW