Datasheet

Real Time Clock (RTC)
Data Sheet MC68HC908LJ24/LK24 — Rev. 2.1
222 Real Time Clock (RTC) Freescale Semiconductor
Figure 12-2. RTC Block Diagram
1Hz
128 Hz
INTERRUPT
TBH = 0 => X,Y = A
TBH = 1 => X,Y = B
DAY-OF-WEEK COUNTER REGISTER
ALARM HOUR REGISTER
COMPARATOR
MINIE
MINF
CHRE
HOUR COUNTER REGISTER
SECOND COUNTER REGISTER
DAY COUNTER REGISTER
MONTH COUNTER REGISTER
YEAR COUNTER REGISTER
CHRONOGRAPH DATA REGISTER
LOGIC
ALARM MINUTE REGISTER
COMPARATOR
MINUTE COUNTER REGISTER
HRIE
HRF
SECIE
SECF
DAYIE
DAYF
TB1IE
TB1F
TB2IE
TB2F
CHRIE
CHRF
ALMIE
ALMF
CGMXCLK
CHRONOGRAPH COUNTER
CHRCLR
INTERNAL BUS
÷ 2 ÷ 2 ÷ 2 ÷ 2÷ 2 ÷ 2÷ 256
25
32
×
16
32
+
X
Y
X
A
Y
A
X
B
Y
B
2Hz
4Hz
8Hz
16Hz
(32.768kHz)
TBH
SL
CLOCK CALIBRATION
CALIN
COMPENSATION CIRCUIT
CALOUT
AND
1Hz
FROM CLOCK
COMPENSATION CIRCUIT
REFERENCE
1Hz
TO CLOCK
COUNTERS
1/100 SECONDS