Real-Time Clock
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
8-12
8.4
Initialization/Application Information
8.4.1
RTC Register Access Protocol
1. Perform dummy read access to a non-RTC address location.
2. Perform dummy read to the targeted RTC address location.
3. Perform actual read or write access to the targeted RTC address location.
Steps 1 and 2 can be combined into one cycle that is a dummy read access to a non-RTC but targeted RTC
address location. Then the protocol is:
1. Perform dummy read access to a non-RTC, targeted RTC address location.
2. Perform actual read or write access to targeted RTC address location.
8.4.2
Flow Chart of RTC Operation
shows the flow chart of a typical RTC operation.
Figure 8-12. Flow Chart of RTC Operation
8.4.3
Code Example for Initializing the Real-Time Clock
shows sample code for initializing the RTC.
Configure RTC Control Register
Config RTC Days Counter Register
Config RTC Hr/Min Counter Register
Config RTC Alarm Registers
Config RTC Interrupt Enable Reg
Check RTC Interrupt Status Register
Config RTC Seconds Counter Reg
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60
