SH3000UM SEMTECH [Semtech Corporation], SH3000UM Datasheet - Page 18

• Manufacturer Part Number: SH3000UM
• Manufacturer: SEMTECH [Semtech Corporation]

Real-Time Clock
Using the ±4ppm, 32.768kHz clock from the LF oscillator, the Real-Time Clock module keeps time with a maximum
error as low as two minutes per year. This compares favorably with a conventional error of two minutes per month for
the typical RTC chip.
The hardware of the Real-Time Clock is capable of 179-years of calendar operations (see Figure 6). All counting-chain
values are loaded at the same time into corresponding registers when the Fractions register is read. All values from
registers are loaded into the counting-chain when the Fractions register is written. The RTC continues normal opera-
tions when V
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POWER MANAGEMENT
Application Information
32.768 kHz
LSB
DD
Fractions
0 - 255
(BIN)
is absent, if backup power is available.
256
1 Hz
Seconds
(BCD)
0 - 59
128
60
Figure 6. Real Time Clock and Periodic Interrupt / Wakeup timer
256 Hz
Minutes
(BCD)
(continued)
0 - 59
60
(BCD)
0 - 23
Hours
24
16-bit Counter
Days (BIN)
0 - 65535
Not authorized for release outside of Semtech
18
LSB
LSB
R
ESET
L
L
OAD
OAD
32-bit Time Interval
32-bit Comparator
32-bit Counter
32-bit Latch
32-bit Latch
MSB
MSB
Current Timer
Interrupt
Value
Serial I/O
Logic
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SH3003
IO/I
- DRAFT
14
NT