sh3001imltrt Semtech Corporation, sh3001imltrt Datasheet - Page 5

• Manufacturer Part Number: sh3001imltrt
• Description: Sh3001 Microbuddy Real-time Clock And Clock Management Support Ic For Microcontrollers
• Manufacturer: Semtech Corporation

Clock Management System
managing clocks, a versatile and accurate “any
frequency” clock synthesizer (see Figure 1).
range of 62.5 kHz to 16.0 MHz, with worst-case
resolution of 0.0256% (256 ppm). The internal
32.768 kHz clock can also be routed to the CLK
(and HF oscillator stopped for energy savings).
Management System are aimed towards the systems
that utilize a microcontroller, a microprocessor, a DSP or
an ASIC.
intentions of the host processor, an industry first. The
SH3001 shuts down its clock output when it senses that
the host processor issued a STOP instruction.
Subsequently, the SH3001 idles, consuming less than
10 µA. As soon as the host exits the STOP mode, the
SH3001 instantaneously starts to supply a stable clock
(<2µs wake-up).
resonator or a crystal as the frequency determining
element, must wait at least several hundred
microseconds (for a resonator), or as much as 100 ms or
more (for a HF crystal), to re-start the oscillator. The
SH3001 allows the response to and service of an event
to finish with a speed previously unattainable for a
simple microprocessor. A system with a traditional clock
approach can be as much as 100x – 10,000x slower.
Copyright ©2002-2005 Semtech Corporation
SYSTEM MANAGEMENT
32.768 kHz
The SH3001 provides a flexible tool for creating and
It is capable of generating any frequency in the
The objectives, features, and behavior of the Clock
The SH3001 permits the automatic sensing of the
A typical system, constructed with a ceramic
16
From / To
Serial I/O
2048 Hz
Frequency Locked Loop
Frequency
Set value
13-bit
Logic
Figure 1. Simplified HF Oscillator System
OUT
FLL On
pin
5
Random Noise
8-bit Pseudo-
Generator
Clock Generator Operation
constructed from the 2:1 tunable 8.0 –16.0 MHz HF
oscillator followed by a programmable “power-of-two”
post-divider (see Figure 1).
post-scale divider allow instantaneous switching
between the 32.768 kHz internal clock and divided-down
HF oscillator output. There is no settling or instability
when the switch occurs.
computing systems, when the large ratio between high
and low frequency of operations allows for
correspondingly large and instantaneous savings in
power consumption.
8, 16, 32, 64, 128)
The frequency synthesizer in the SH3001 is
The Clock Source selector and the programmable
This is a preferred method for clock control in
(Divide by 1, 2, 4,
DCO Code
Register
18-bit
Post-scaler
Spreading
Clock Source
Spectrum
Controls
SH3001 MicroBuddy™
1
0
V1.15
Clock Buffer
HF Digitally
Controlled
8-16 MHz
Oscillator
and Glue
Logic
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Clock On
S
TART
/S
CLK
16
CLK
15
DCO On
TOP
Force
OUT
IN