Datasheet

Real Time Clock (RTC)
MC68HC908LJ12 — Rev. 2.1 Technical Data
Freescale Semiconductor Real Time Clock (RTC) 213
Figure 12-2. RTC Block Diagram
000
÷ 256
÷ 320
÷ 640
÷ 384
÷ 768
100/110
010
101/111
011
1 Hz
4 Hz
2 Hz
100 Hz / 128 Hz
A
B
SL
X
XTL[2:0]
INTERRUPT
25
32
×
XTL[2:0] = 000 => X = A
XTL[2:0] = 000
=> X = 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
÷ 4
÷ 5
÷ 6
÷ 2
÷ 2
÷ 32
÷ 25
÷ 2 ÷ 2
X
× 1
÷ 64
CHRONOGRAPH COUNTER
CHRCLR
INTERNAL BUS
RTCE
32.768 kHz
32.000 kHz
38.400 kHz
64.000 kHz
76.800 kHz
VALID CGMXCLK
FREQUENCIES: