ADSP-214xx SHARC Processor Hardware Reference 18-5
Real-Time Clock—ADSP-2147x
Digital Watch
The ADSP-2147x RTC provides a set of digital watch features. The inter-
nal oscillator generates a 32768 Hz signal using the crystal which is scaled
down to 1Hz and used to clock the second, minute, hour and day coun-
ters. The 32768-day counter is incremented each day at midnight (during
change from 23:59:59). The counter operates on the RTC supply (either
Figure 18-1. RTC Block Diagram
DAYS
COUNTER
ALARM
EVENT
24 HOURS
EVENT
9
RTC_ALARM REGISTER
EQUAL?
HOURS
COUNTER
MINUTES
COUNTER
SECONDS
COUNTER
HOURS
EVENT
MINUTES
EVENT
SECONDS
EVENT
5
66
956
6
DAY ALARM
EVENT
YYYY
RTXI
32.768 kHz
1 Hz
TICK
SET
RST
STOPWATCH
EVENT
Y
16
STOPWATCH
COUNTER
WRITE
RTC_SWCNT
EQUAL?
NORMAL
COUNTDOWN
EQUAL 0?
EQUAL? EQUAL?