Datasheet

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Data Sheet 24 1999-07
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Real Time Clock
The Real Time Clock (RTC) module of the C161PI consists of a chain of 3 divider blocks,
a fixed 8:1 divider, the reloadable 16-bit timer T14, and the 32-bit RTC timer (accessible
via registers RTCH and RTCL). The RTC module is directly clocked with the on-chip
oscillator frequency divided by 32 via a separate clock driver (
I
RTC
= I
OSC
/ 32) and is
therefore independent from the selected clock generation mode of the C161PI. All timers
count up.
The RTC module can be used for different purposes:
• System clock to determine the current time and date
• Cyclic time based interrupt
• 48-bit timer for long term measurements
Figure 8 RTC Block Diagram
Note: The registers associated with the RTC are not effected by a reset in order to
maintain the correct system time even when intermediate resets are executed.
RTCLRTCL
T14
T14REL
8:1
f
RTC
Reload
Interrupt
Request