Freescale Semiconductor ColdFire MCF52210 - Manual (Page 162)

Real-Time Clock
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
11-2 Freescale Semiconductor
11.1.3 Modes of Operation
The incoming 1 Hz signal is used to increment the seconds, minutes, hours, and days TOD counters. The
alarm functions, when enabled, generate RTC interrupts when the TOD settings reach programmed values.
The sampling timer generates fixed-frequency interrupts, and the minute stopwatch allows for efficient
interrupts on minute boundaries.
• Counter
The counter portion of the RTC module consists of four groups of counters that are physically
located in three registers:
— The 6-bit seconds counter is located in the SECONDS register
— The 6-bit minutes counter and the 5-bit hours counter are located in the HOURMIN register
— The 16-bit day counter is located in the DAYR register
• Alarm
There are three alarm registers that mirror the three counter registers. An alarm is set by accessing
the real-time clock alarm registers (ALRM_HM, ALRM_SEC, and DAYALARM) 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.
• Minute Stopwatch
The minute stopwatch performs a countdown with a one minute resolution. It can be used to
generate an interrupt on a minute boundary.
11.2 Memory Map/Register Definition
The RTC module includes 10 32-bit registers. Table 11-1 summarizes these registers and their addresses.
11.2.1 Register Descriptions
This section consists of register descriptions in address order. Each description includes a standard register
diagram with an associated figure number. Details of register bit and field function follow the register
diagrams, in bit order.
Table 11-1. RTC Module Register Memory Map
IPSBAR Offset Use Access
0x03C0 RTC Hours and Minutes Counter Register (HOURMIN) read/write
0x03C4 RTC Seconds Counter Register (SECONDS) read/write
0x03C8 RTC Hours and Minutes Alarm Register (ALRM_HM) read/write
0x03CC RTC Seconds Alarm Register (ALRM_SEC) read/write
0x03D0 RTC Control Register (RTCCTL) read/write
0x03D4 RTC Interrupt Status Register (RTCISR) read/write
0x03D8 RTC Interrupt Enable Register (RTCIENR) read/write
0x03DC Stopwatch Minutes Register (STPWCH) read/write
0x03E0 RTC Days Counter Register (DAYS) read/write
0x03E4 RTC Day Alarm Register (ALRM_DAY) read/write
0x03F0 Reserved —
0x03F4 RTC General Oscillator Count Upper Register (RTCGOCU) read/write
0x03F8 RTC General Oscillator Count Lower Register (RTCGOCL) read/write