TMP91C824
91C824-195
3.13
Real time clock (RTC)
3.13.1
Function description for RTC
1) Clock function (hour , minute , second)
2) Calendar function (month and day , day of the week , and leap year)
3) 24 or 12-hour (AM/PM) clock function
4) ± 30 second adjustment function (by software)
5) Alarm function (Alarm output)
6) Alarm interrupt generate
3.13.2
Block diagram
Figure 3.13.1 RTC block diagram
(note1) The Christian era year column:
This product has year column toward only lower two columns. Therefore the next
year in 99 works as 00 years. In system to use it, please manage upper two
columns with the system side when handle year column in the Christian era.
(note2) Leap year:
A leap year is the year, which is divisible with 4, but the year, which there is
exception, and is divisible with 100 is not a leap year. However, the year, which is
divisible with 400, is a leap year. But there is not this product for the correspondence
to the above exception. Because there are only with the year which is divisible with
4 as a leap year, please cope with the system side if this function is problem.
1S CARRY
HOLD
ADJUST
CARRY
HOLD
ALARM REGISTER
TIMER
COMPARATOR
Divider
32KHz
CLOCK: fs
INTRTC
ADJUST
READ/WRITE
CONTROL
ADDRESS
BUS
DATA BUS
WR
D0
〜
D7
Address
RD
ALARM
SELECT
16Hz
Clock
1Hz Clock
/ALARM
/ALARM