
XC2220L, XC2224L
XC2000 Family / Econo Line
Functional Description
PRELIMINARY
Data Sheet
43
V1.0, 2010-12
3.10
Real Time Clock
The Real Time Clock (RTC) module of the XC222[04]L can be clocked with a clock signal
selected from internal sources or external sources (pins).
The RTC basically consists of a chain of divider blocks:
Selectable 32:1 and 8:1 dividers (on - off)
The reloadable 16-bit timer T14
The 32-bit RTC timer block (accessible via registers RTCH and RTCL) consisting of:
– a reloadable 10-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 only affected by a power reset.
CNT-Register
REL-Register
10 Bits
6 Bits
10 Bits
T14
M CB05568B
T14-Register
Interrupt Sub Node
RTCINT
MUX
32
PRE
RUN
CNT
INT3
CNT
INT2
CNT
INT1
CNT
INT0
f
CNT
f
RTC
T14REL
10 Bits
6 Bits
10 Bits
:
MUX
8
:
REFCLK