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Real-Time Clock
Freescale Semiconductor
28-13
28.4.4
Minute Stopwatch
The minute stopwatch performs a countdown with a one minute resolution. It can generate an interrupt on
a minute boundary. For example, to turn off a peripheral after five minutes of inactivity, program a value
of 0x04 into RTC_STPWCH[CNT]. At each minute, the value in the stopwatch decrements. When the
stopwatch value reaches -1, interrupt occurs. The value of the register does not change until it is
reprogrammed. The actual delay includes the seconds from setting the stopwatch to the next minute tick.
28.5
Initialization/Application Information
28.5.1
Flow Chart of RTC Operation
shows the flow chart of a typical RTC operation.
Figure 28-14. Flow Chart of RTC Operation
28.5.2
Programming the Alarm or Time-of-Day Registers
Use the following procedure illustrated in
when changing the alarm or time-of-day (day,
hour, minute, and second) registers.
Configure RTC_CR
Configure RTC_DAYS
Configure RTC_SECONDS
Configure RTC_HOURMIN
Configure RTC Alarm Registers
Configure RTC_IER
Check RTC_ISR
Apply RTC Oscillator Clock
Configure RTC_GOCU and RTC_GOCL
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...