MC68HC908LJ24 Datasheet, PDF (231/464 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Real Time Clock (RTC)
RTC Registers
12.10.1 RTC Calibration Control Register (RTCCOMR)
The RTC calibration control register (RTCCOMR) contains control bits
for RTC calibration, output option for the CALOUT pin, and registers/bits
write-protect enable.
Address: $0040
Read: 0
Write: R
0
0
0
CAL* AUTOCAL* OUTF1* OUTF0*
R
RTCWE1 RTCWE0
Reset: 0
0
0
0
0
0
0
0
* CAL, AUTOCAL, and OUTF{1:0] bits are write-protected; unprotect by a write sequence to RTCWE[1:0].
Figure 12-6. RTC Calibration Control Register (RTCCOMR)
CAL — RTC Calibration Mode
This read/write bit enables the RTC calibration circuit. The CAL bit is
cleared automatically after completion of automatic calibration if
AUTOCAL is also set when CAL bit is set.
1 = RTC calibration mode enabled
0 = RTC calibration mode disabled
AUTOCAL — RTC Automatic Calibration Enable
This read/write bit enables the CALIN pin to accept an incoming
1-Hz signal and calibration circuits for RTC automatic calibration. This
bit can only be set when the CAL bit is set. After calibration (approx.
15 seconds), the AUTOCAL bit is automatically cleared.
1 = RTC automatic calibration enabled
0 = RTC automatic calibration disabled
NOTE: RTC clock and calendar functions are not affected when calibration is
enabled.
MC68HC908LJ24/LK24 — Rev. 2
MOTOROLA
Real Time Clock (RTC)
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Data Sheet
231