Fujitsu MB91460 SERIES FR60 User Manual page 968

Chapter 49 Real-Time Clock
4.Registers
When the minute counter overflows, this flag is set to "1".
• bit10: 1-minute interrupt request flag
INT1
0 No interrupt requests
1 Generate interrupt requests at 1-minute intervals.
• bit9: Enable interrupt requests at 1-second intervals
INTE0
0 No interrupt requests
1 Generate interrupt requests at 1-second intervals.
When the 21 bit down counter is set to "0", this flag is set to "1".
• bit8: 1-second interrupt request flag
INT0
0 No interrupt requests
1 Generate interrupt requests at 1-second intervals.
• bit7-5: Reserved
Be sure to write "0". The read value is the value written.
• bit4 Undefined
:
Writing does not affect the operation. The read value is indeterminate.
• bit3: Operation status
RUN
0 The Real-time Clock module is inactive.
1 The Real-time Clock module is active.
• bit2: Update
UPDT
0 The update has been completed. (Writing "0" does not affect the operation.)
Update the hour/minute/second counters with the values of the hour/minute/second registers,
1
respectively.
Before writing "1" to the update bit (UPDT), the hour/minute/second registers must be set to the values with
which to update the hour/minute/second counters. The hour/minute/second registers are updated on
reloading to the 21 bit down counter.
• bit1 Undefined
:
Writing does not affect the operation. The read value is indeterminate.
• bit0: Start
ST
The Real-time Clock module stops to operate, and the 21 bit down counter and the hour/minute/second
0
counters are cleared.
The settings of the hour/minute/second registers are loaded to the hour/minute/second counters, and the
1
Real-time Clock module starts to operate.
Application Note: The Sub-second register of the RTC module stores the reload value for the 21bit
prescaler. This value is reloaded after the reload counter reaches "0". When modifying all three bytes, make
sure the reload operation will not be performed in between the write instructions. Otherwise the 21-bit
prescaler loads the incorrect value of the combination of new data and old data bytes. It is generally
952
Operation
Read
Operation
Status
Read
Status
Status/Operation
Operation
Write
Clear the flag.
Writing does not affect the operation.
Write
Clear the flag.
Writing does not affect the operation.