Microcontroller Solutions TechZone Magazine, April 2011 - Digikey

Table of Contents
Digi-Key Features
Editorial Comment ................................................... 5
Microcontroller TechZone SM Q & A ............................
6
Trivia Contest ......................................................... 39
Innovations in Connectivity:
a look inside Digi-Key’s
state-of-the-art Weather Center ............................. 47
The Ultra-Low-Power USB Revolution ......................... 7
by Bhargavi Nisarga, Keith Quiring, and Les Taylor, Texas Instruments
USB is a fast, convenient connectivity interface, but until recently it
hasn’t been associated with low-power. New MCUs have made it an
attractive choice for ultra-low-power embedded applications.
USB-Based Temperature Monitor .............................. 12
contributed by Analog Devices
If you need to be able to detect small variations in temperature, an
RTD or thermocouple won’t do it. Using a thermocouple, an analog
MCU, an LDO and a few discretes, you can construct a highly accurate
temperature sensing application.
Introducing a Second MCU
to Embedded Designs ................................................. 15
by Nicholas Cravotta
Adding a second MCU to your embedded design addresses a number
of design issues, but not without adding some complex new ones.
This article focuses on inter-processor communications and how to
both avoid and/or solve the issues that arise.
Eliminating the Parallel/Serial Tradeoff
in Embedded Systems with
SPIFI-Equipped Cortex-M3 ......................................... 19
by Rob Cosaro and Gene Carter, NXP Semiconductors
The SPIFI peripheral creates a way for designers to use a small,
inexpensive serial fl ash where they might previously have needed
to use a larger, more expensive parallel fl ash to meet the system’s
performance requirements.
ColdFire Ethernet for Diverse Applications ................ 26
by Eric Gregori, Freescale Semiconductor
Adding Ethernet to embedded products provides a level of
connectivity never before available in the embedded space. This
article provides a detailed tutorial, an example application and XML
code to quickly get you comfortable with embedded Ethernet.
Your MCU is Just Starting to be Connected ............... 36
by Tom Starnes, Industry Analyst, Objective Analysis
Embedded applications, like individual PCs, become more useful
when they can communicate with other devices. A wide range of
protocols has been developed to enable such communication, but that
work is far from over.
Deeply Embedded Devices:
The “Internet of Things” ............................................. 40
by Mark Wright and Rodger Richey, Microchip Technology Inc.
Wi-Fi has long worked well to connect PCs and embedded devices.
However, it’s not known for being low-power and is hardly an obvious
choice for deeply embedded devices. That’s about to change.
Peripheral Reflex System
Avoids MCU Overload ................................................. 44
contributed by Energy Micro
Energy Micro’s Peripheral Refl ex System minimizes MCU loading by
enabling peripheral modules to communicate with each other without
processor intervention. This article details how it works and why.
CAN Primer: Creating Your Own Network .................. 48
by Bob Boys, ARM
CAN is a sophisticated network well suited to any number of
automotive, industrial and consumer applications. This article takes
an in-depth look at the protocol, its implementations and implications
for embedded designs.
Power Debugging ARM Cortex-M3
and Cortex-M4 Applications ...................................... 58
by Lotta Frimanson and Anders Lundgren, IAR Systems
Power debugging is based on the ability to sample the power
consumption of a system and correlate each sample with the source
code. ARM Cortex-M3 and –M4 cores provide the architectural hooks
and IAR provides the software to make this possible.
The Heartbeat Behind
Portable Medical Devices: Ultra-Low-Power
Mixed-Signal Microcontrollers .................................. 61
by Shahram Tadayon, Silicon Laboratories
In the medical device market, products must combine accurate
analog measurements with high reliability and ultra-low-power
consumption. Fortunately, there are some integrated mixed-signal
MCUs that can deliver on all three requirements.
USB 3.0—Are We There Yet ...................................... 64
by John Donovan, Low-Power Design
SuperSpeed USB promises a 10x speed improvement over USB 2.0
while maintaining compatibility with legacy devices. If your next
application involves streaming video, take a look at what it has to offer.
4