Real Time Clock Operation Description - Samsung S3C2416 User Manual

REAL TIME CLOCK

1.2 REAL TIME CLOCK OPERATION DESCRIPTION

TICNT
XTIrtc
XTOrtc
1.2.1 Leap Year Generator
The leap year generator can determine the last date of each month out of 28, 29, 30, or 31, based on data from
BCDDAY, BCDMON, and BCDYEAR. This block considers leap year in deciding on the last date. An 8-bit counter
can only represent 2 BCD digits, therefore it cannot decide whether "00" year (the year with its last two digits
zeros) is a leap year or not. For example, it cannot discriminate between 1900 and 2000. To solve this problem,
the RTC block in S3C2416 has hard-wired logic to support the leap year in 2000. Note 1900 is not leap year while
2000 is leap year in general Gregorian calendar. Therefore, two digits of 00 in S3C2416 denote 2000, not 1900.
So, RTC in S3C2416 supports from 1901 to 2099.
13-2
Time Tick Generator
32KHz~1Hz
2 15 Clock
Divider
1 Hz
Control
Register
RTCCON
Figure 13-1. Real Time Clock Block Diagram
RTCRST
Reset
Register
SEC MIN HOUR
Alarm Generator
ALMWKUP
S3C2416X RISC MICROPROCESSOR
Leap Year Generator
DATE DAY MON
ALMINT
TICWKUP
TICINT
YEAR
RTCALM