SH3000EK SEMTECH [Semtech Corporation], SH3000EK Datasheet - Page 10

• Manufacturer Part Number: SH3000EK
• Description: Reset Management and Clock Management Support IC for Microcontrollers
• Manufacturer: SEMTECH [Semtech Corporation]

Periodic Interrupt / Wakeup Timer
Timer can be used to create very accurate recurring
interrupts for use by the host micro. With some minimal
software support from the host processor, it can also be
used to create alarms, with practically unlimited duration.
halted, consuming no energy. The interrupt wakes up
the processor, which can perform the requisite task and
go back to sleep, until the next periodic interrupt.
average power consumption.
minimum interval of 30.5 µs and the maximum interval of
36.4 hours, creates the Timer.
for the time interval is written into the 4-byte Time
Interval register. When the least significant byte (LSB) is
written, the whole value is moved to the Time Interval
latch, the counter is reset and starts to increment with
the 32.768 kHz clock.
Copyright ©2002-2005 Semtech Corporation
SYSTEM MANAGEMENT
Simple and versatile, the Periodic Interrupt / Wakeup
While the timer is running, the host processor can be
This mode of operation can achieve extremely low
A 32-bit counter clocked by 32.768 kHz, producing a
After reset, the Timer is stopped until the new value
32.768 kHz
LSB
LSB
10
Figure 6. Periodic Interrupt / Wakeup timer
R
ESET
When the 32-bit comparator detects a match, an
interrupt is generated and the counter is reset and starts
the next timing cycle.
current value from the counter can be read at any time.
The whole 32-bit value is loaded into the 32-bit Current
Timer Value latch when the least significant byte is read.
This prevents errors stemming from the finite time
between the readings of individual bytes of the current
value.
Auxiliary functions
Voltage Regulator
Pin V
voltage or a supply source for small loads (<2 mA). A
bypass capacitor might be necessary between this pin
and V
a low ripple reference is required.
L
L
OAD
OAD
32-bit Time Interval
32-bit Comparator
Although the counter cannot be written to, the
32-bit Counter
32-bit Latch
32-bit Latch
REG
SS
if the load generates large current transients or
can be used as a nominal 2.20 V reference
SH3002 MicroBuddy™
MSB
MSB
V1.20
Current Timer
Interrupt
Value
Serial I/O
Logic
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