SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 256

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

Note: The RTC registers are not affected by a reset. After a power on reset, however,
Figure 14-2 RTC Block Diagram
System Clock Operation
A real time system clock can be maintained that keeps on running also during idle mode
and power down mode (optionally) and indicates the current time and date. This is
possible because the RTC module is not affected by a reset.
The maximum resolution (minimum stepwidth) for this clock information is determined by
the input clock of timer T14. The maximum usable timespan is achieved when T14REL
is loaded with 0000
Cyclic Interrupt Generation
The RTC module can generate an interrupt request whenever timer T14 overflows and
is reloaded. This interrupt request may be used, for example, to provide a system time
tick independent of the CPU frequency without loading the general purpose timers, or to
wake up regularly from idle mode. The interrupt cycle time can be adjusted via the timer
T14 reload register T14REL. Please refer to “RTC Interrupt Generation” below for more
details.
48-bit Timer Operation
The concatenation of the 16-bit reload timer T14 and the 32-bit RTC timer can be
regarded as a 48-bit timer which is clocked with the RTC input frequency divided by the
fixed prescaler. The reload register T14REL should be cleared to produce a 48-bit binary
timer. However, any other reload value may be used.
The maximum usable timespan is 2
than 100 years at an oscillator frequency of 20 MHz.
User’s Manual
they are undefined.
Reload
H
and so T14 divides by 2
T14REL
RTCH
T14
48
( 10
14-2
14
) T14 input clocks, which would equal more
16
RTCL
8:1
.
f
C164CM/C164SM
RTC
Interrupt
Request
MCD04432
Real Time Clock
Derivatives
V1.0, 2002-02