SH3000UM SEMTECH [Semtech Corporation], SH3000UM Datasheet - Page 9

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

The SH3003 is a single-chip support system for
microcontrollers, microprocessors, DSPs and ASICs. It
consists of four major functional blocks, each block having
numerous enhancements over alternative solutions.
The major modules are the CPU Supervisor, the Clock
Management System, the Real-Time Support, and the
Auxiliary functions.
The entire chip is controlled by the set of internal registers
and accessed via the single-pin serial interface. All of
the settings, confi guration, and calibration or operating
parameters are programmable and re-programmable
at any time. All of the parameters required for stand-
alone operations are initialized on reset from the built-
in factory-programmed nonvolatile memory. This allows
the SH3003 to operate autonomously for most of its
supervisory functions. The stand-alone operations do
not require the use of the serial interface or any of the
initialization and control operation, but without these, the
full potential benefi t of the SH3003 may not be realized.
In the preferred confi guration, where the SH3003 is
tightly coupled to the target micro, the SH3003 offers
an unprecedented level of design fl exibility in clock and
power usage management.
The SH3003 is a particularly desirable integration because
the built-in features interact and meld to produce more
useful system level functions.
For example, on power-up, the SH3003 can quickly release
the reset lines on its CPU Supervisor module because
the clock signal from the Clock Management System is
guaranteed to be running and stabilized. An ordinary
reset circuit must hold reset active for a long time to allow
an unknown crystal to start up and stabilize.
©2006 Semtech Corp.
POWER MANAGEMENT
POWER MANAGEMENT
Application Information
9
Default start-up parameters for the SH3003 are:
Internal load capacitors on the 32.768kHz crystal
oscillator pins are set to 12.5pF.
The SH3003 offers several ways to minimize system
power consumption, such as allowing the target processor
to enter deep sleep by stopping its clock completely,
and to wake up as often as necessary with no external
support. The clock can be programmed to start up at a
given frequency, and software can adjust it dynamically
to manage power consumption and different operating
modes.
Users should consider the interactions of the major
functional blocks to gain the maximum advantage
from the SH3003. The individual functional blocks are
described in the following sections.
Default Start-Up Parameters
While the operating parameters of the SH3003 are
programmable by the host microcontroller at any
time, the default start-up parameters and appropriate
calibration values are programmed into the chip’s non-
volatile memory at the factory. This enables the SH3003
to be used stand-alone or in an embedded application
with minimal microprocessor intervention.
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Reset and V
CLK
CLK32 output is disabled
Spread spectrum is disabled
Internal RC oscillator is calibrated (to nominal
frequency of 32768Hz
OUT
frequency is 16.0MHz
BO
voltage level is 2.3V
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SH3003