s3c2410a Samsung Semiconductor, Inc., s3c2410a Datasheet - Page 422

• Manufacturer Part Number: s3c2410a
• Description: 16/32-bit Risc Arm Microprocessor
• Manufacturer: Samsung Semiconductor, Inc.

REAL TIME CLOCK (RTC)
S3C2410A
REAL TIME CLOCK OPERATION
TICNT
TIME TICK
Time Tick Generator
128 Hz
RTCRST
15
2
Clock Divider
Reset Register
Leap Year Generator
XTIrtc
1 Hz
XTOrtc
SEC
MIN
HOUR
DATE
DAY
MON
YEAR
Control Register
Alarm Generator
RTCCON
RTCALM
PMWKUP
PWDN
ALMINT
Figure 17-1. Real Time Clock Block Diagram
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
BCDDATE, BCDMON, and BCDYEAR. This block considers leap year in deciding on the last date. An 8-bit counter
can only represent 2 BCD digits, so 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 S3C2410A has hard-wired logic to support the leap year in 2000. Note 1900 is not leap year while 2000 is leap
year. Therefore, two digits of 00 in S3C2410A denote 2000, not 1900.
17-2