Datasheet

Real Time Clock (RTC)
Data Sheet MC68HC908LJ24/LK24 — Rev. 2.1
232 Real Time Clock (RTC) Freescale Semiconductor
OUTF[1:0] — Calibration Mode CALOUT Pin Output Selection
These two bits select the output option for the CALOUT pin.
When CAL = 0, OUTF[1:0] is always 00.
RTCWE[1:0] — RTC Module Write Enable
These two write-only bits control the write-protect function of several
RTC registers and bits. After a reset, write-protect is disabled,
allowing full write access to RTC registers and bits. These two bits
always read as 0.
To enable write-protect, perform the following sequence:
1. Write %10 to RTCWE[1:0] bits
2. Write %10 to RTCWE[1:0] bits
To disable write-protect, perform the following sequence:
1. Write %00 to RTCWE[1:0] bits
2. Write %01 to RTCWE[1:0] bits
3. Write %11 to RTCWE[1:0] bits
4. Write %10 to RTCWE[1:0] bits
To disable write-protect from an unsure protection state, first perform
the enable write-protect sequence, followed by the disable write-
protect sequence.
Table 12-4. CALOUT Pin Output Option
OUTF[1:0] CALOUT Pin Output
00 CALOUT pin is disconnected.
01 CALOUT pin outputs compensated 1-Hz.
10 CALOUT pin outputs CGMXCLK clock.
11 Reserved