Datasheet

XC167CI-16F
Derivatives
Functional Description
Data Sheet 42 V1.3, 2006-08
3.9 Real Time Clock
The Real Time Clock (RTC) module of the XC167 is directly clocked via a separate clock
driver either with the on-chip auxiliary oscillator frequency (
f
RTC
= f
OSCa
) or with the
prescaled on-chip main oscillator frequency (
f
RTC
= f
OSCm
/32). It is therefore independent
from the selected clock generation mode of the XC167.
The RTC basically consists of a chain of divider blocks:
• a selectable 8:1 divider (on - off)
• the reloadable 16-bit timer T14
• the 32-bit RTC timer block (accessible via registers RTCH and RTCL), made of:
– a reloadable 10-bit timer
– a reloadable 6-bit timer
– a reloadable 6-bit timer
– a reloadable 10-bit timer
All timers count up. Each timer can generate an interrupt request. All requests are
combined to a common node request.
Figure 9 RTC Block Diagram
Note: The registers associated with the RTC are not affected by a reset in order to
maintain the correct system time even when intermediate resets are executed.
CNT-Register
REL-Register
10 Bits6 Bits6 Bits10 BitsT14
MCB05568
T14-Register
Interrupt Sub Node
RTCINT
MUX
8
PRE
RUN
CNT
INT3
CNT
INT2
CNT
INT1
CNT
INT0
f
CNT
f
RTC
T14REL 10 Bits6 Bits6 Bits10 Bits
: