
Real-Time Clock
25-2
Freescale Semiconductor
25.1.2
Features
The RTC module includes:
•
Full clock—days, hours, minutes, seconds
•
Minute countdown timer with interrupt
•
Programmable daily alarm with interrupt
•
Sampling timer with interrupt
•
Once-per-day, once-per-hour, once-per-minute, and once-per-second interrupts
•
Operation at 32.768 kHz, 32 kHz, or 38.4 kHz (determined by reference clock crystal)
25.1.3
Modes of Operation
The real-time-clock operates in various modes as described below:
•
Time-of-day counters
— The prescaler divides the reference clock down to 1 Hz. The reference frequencies of
32.768 kHz, 38.4 kHz and 32 kHz are supported.
— The 1 Hz clock increments four counters that are located in three registers
– RTC_SECONDS contains the 6-bit seconds counter
– RTC_HOURMIN contains the 6-bit minutes counter and 5-bit hours counter
– RTC_DAYS contains the 16-bit day counter
•
Alarm
— There are three alarm registers that mirror the three counter registers. An alarm is set by
accessing the real-time clock alarm registers (RTC_ALRM_SEC, RTC_ALRM_HM, and
RTC_ALRM_DAY) and loading the exact time that the alarm should generate an interrupt.
When the TOD clock value and the alarm value coincide, an interrupt occurs.
•
Sampling Timer
— The prescaler divides the reference clock down to 512 Hz. The sampling timer generates a
periodic interrupt with frequencies specified by the RTC_IER[SAM
n
,2HZ] bits. This timer can
be used for digitizer sampling, keyboard debouncing, or communication polling.
lists the interrupt frequencies of the sampling timer for the possible reference clocks.
•
Minute Stopwatch
— The minute stopwatch performs a countdown with a one minute resolution. It generates an
interrupt on a minute boundary.
MCF5329 Reference Manual, Rev 3
Summary of Contents for MCF5329
Page 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...