MC68VZ328 Integrated Processor User's Manual

Programming Model
 Real-Time Clock 11-5
11.2 Programming Model
Section 11.2.1, “RTC Time Register,” through Section 11.2.9, “Stopwatch Minutes Register,” provide
programming information on the real-time clock.
11.2.1 RTC Time Register
The real-time clock hours, minutes, and seconds (RTCTIME) register is used to program the hours,
minutes, and seconds. It can be read or written at any time. After a write, the current time assumes the new
values. This register cannot be reset since the real-time clock is always enabled at reset. The settings for the
RTCTIME register are described in Table 11-2.
RTCTIME RTC Hours, Minutes, and Seconds Register 0x(FF)FFFB00
BIT
31
30 29 28 27 26 25 24 23 22 21 20 19 18 17
BIT
16
HOURS MINUTES
TYPE
rw rw rw rw rw rw rw rw rw rw rw
RESET
000XXXXX00XXXXXX
0xXXXX
BIT
15
1413121110987654321
BIT
0
SECONDS
TYPE
rw rw rw rw rw rw
RESET
0000000000XXXXXX
0x00XX
Table 11-2. RTC Hours, Minutes, and Seconds Register Description
Name Description Setting
Reserved
Bits 31–29
Reserved These bits are reserved and should be set to 0.
HOURS
Bits 28–24
Hours—These bits indicate the current hour. The bits can be set to any value between 0 and
23.
Reserved
Bits 23–22
Reserved These bits are reserved and should be set to 0.
MINUTES
Bits 21–16
Minutes—These bits indicate the current
minute.
The bits can be set to any value between 0 and
59.
Reserved
Bits 15–6
Reserved These bits are reserved and should be set to 0.
SECONDS
Bit 5–0
Seconds—These bits indicate the current sec-
ond.
The bits can be set to any value between 0 and
59.