Registers; Rtc Hours-Minutes-Seconds Register (Rtchms) - Motorola DragonBall MC68328 User Manual

Real-Time Clock
RTC_CLKO
RTC_IRQB INTERRUPT
minute increments, the minute stopwatch value is decremented. The interrupt is generated
when the counter counts to -1.

5.1.4 Registers

There are several registers (described below) associated with the RTC.

5.1.4.1 RTC HOURS-MINUTES-SECONDS REGISTER (RTCHMS).

31 30 29 28
Unused
15 14 13 12
Address: $(FF)FFFB00
The hours, minutes and seconds can be read or written at any time. After a write, the current
time assumes the new values. Unused bits read 0.
HOURS
These 5 bits, when read, indicate the current hour and can be set to any value between 0
and 23.
5-2 MC68328 DRAGONBALL PROCESSOR USER'S MANUAL
32.768 kHz
PRESCALER
38.4 kHz
CLOCK
CONTROL
CONTROL
INTERRUPT
ENABLE
INTERRUPT
STATUS
ADDRESS
EC000
DATA
BUS
DECODE
BUS_CONTROL
Figure 5-1. Real-Time Clock
27 26 25
HOURS
11 10 9
Unused
Figure 5-2. Hours-Minutes-Seconds Register
1 pps
1 ppm
MINUTE
SECOND
ALARM COMPARATOR
SECOND
LATCH
MINUTE STOPWATCH
24 23 22 21
Unused
8 7 6 5
1 pph
HOUR
HOUR
MINUTE
LATCH
LATCH
20 19 18 17
MINUTES
4 3 2 1
SECONDS
Reset Value: $00000000
MOTOROLA
16
0