Eternally yours at 8 bits
Ubiquitous 8-bit microcontrollers live on in a market that won't die
By Stephen Lawton, illustration by Ben Fishman
is said that the more things change, the more they stay the same. In the
world of the 8-bit microcontroller, this truism drives a multi-billion-dollar
Way back in 1980 Intel Corp., Santa Clara, CA, invented the progenitor
of the species, the 8051. Today, the technology originally used in such
8-bit microprocessors as Intel's 8086 and Zilog Inc.'s Z-80 lives on in
microcontrollers found virtually everywhere.
In fact, look around your office or home, and you'll see plenty of applications
of these chips (see "At home with MCUs," below). These 8-bit microcontroller
units (MCUs) are in everything from giveaway toys from the local fast-food
restaurant to the space shuttle. The $70,000 BMW 745i premium luxury sedan
has nearly five dozen 8-bit MCUs, not to mention another dozen or so 32-
and 16-bit MCUs that manage key motor and transmission functions.
This is a market that may never die. Ever since Intel launched the 8051,
the 8-bit MCU segment has blossomed and continues to this day to reinvent
itself and garner new applications.
The 8-bit MCU has become the cornerstone of the embedded market. For products,
or applications within a product that have relatively simple, specific
processing needs, the 8-bit MCU is often the chip of choice for design
engineers. The reason is simple: It's cheap-costing from 60 cents to $2.50
per unit in volume-and it contains an entire computer's primary functions
on one chip. The 8-bit MCU can handle anywhere from four to more than
60 I/O channels as well as memory, peripherals, timers, analog-to-digital
converters and other functions. This little wonder has enabled consumer
and industrial product manufacturers to build goods that might never have
seen the light of the marketplace had they depended on microprocessors,
external memory chips and all of the requisite support chips.
Worldwide 8-bit MCU sales were about $5.5 billion last year, more than
half of the total worldwide MCU revenue of $10.9 billion, according to
Tom Starnes, chief analyst for microprocessors, microcontrollers and digital
signal processors at Gartner Dataquest Inc., Austin, TX. Microcontroller
revenue is down 27% from 2000, he says, due to the weakness in the technology
sector and economy as a whole. This year sales will be flat, but Starnes
projects that as the economy rebounds MCUs will once again reach their
2000 levels, probably in 2003 or 2004.
Dominating the 8-bit segment is Motorola Inc., Schaumburg, IL, which garners
23% of the market. The company with the second highest market share, Hitachi
Ltd., has only 9%. Then come NEC Corp., Microchip Technology Inc., Mitsubishi
and STMicroelectronics NV , according to Dataquest (see table, below).
As a group, these companies represent 50% to 60% of the MCU market, Starnes
says. Some 40 other companies fill out the rest of the MCU market.
What makes 8-bit MCUs so versatile is their low cost and, well, their
eight bits, says Dave Yeskey, a vice president at Chandler, AZ-based Microchip
Technology. "Most [design engineers] are used to dealing with 1-byte words,"
he says. A single byte (eight bits) of data is "more than adequate" for
handling functions that are not time-sensitive, he notes.
To infinity, and beyond
That doesn't mean they can't be used in real-time situations as well.
In fact, when 77-year-old former senator John Glenn became the oldest
U.S. astronaut during his 1998 Shuttle Discovery mission, he wore a monitor,
powered by a Microchip 8-bit MCU, which tracked his body temperature.
That 8-bit MCU sells for about $1, according to Norbert Ohlenbusch, a
systems architect at Personal Electronics Devices (PED) Inc., Wellesley,
MA, which made the monitor.
Back on earth, Meade Instruments Corp., Irvine, CA, uses multiple 8-bit
MCU slaves connected to a master 8-bit MCU in its consumer telescopes
to perform such tasks as moving the telescope and maintaining the proper
focus. Using multiple MCUs lowers the risk of product failure, because
each processor is responsible for just a few functions. Units that use
a single, high-end MCU to manage all functions would be prone to more
errors, says Ken Baun, Meade's senior vice president of engineering. The
8-bit devices also save room because they fit in what otherwise might
be unused space. A single, multifunction microprocessor or larger MCU
would require a large motherboard, making the product larger, possibly
more expensive and likely less reliable, he notes.
don't need to keep lots of components in stock. Sometimes we use exactly
the same [MCUs] with slight program modifications" in different telescopes.
-Ken Baun, senior vice president
of engineering, Meade Instruments Corp.
Meade could have used a more powerful MCU to determine a planet's position
in the sky in real time, Baun says, but instead the company opted for
a smaller MCU and a list of precalculated tables. Instead of the MCU constantly
calculating the exact position of the planet in the sky, the user sets
his latitude and longitude, then the telescope's electronics query a set
of look-up tables to determine the correct position in the sky, a function
well suited to the MCU, Baun says.
The MCUs in Meade's telescopes cost from $.80 to $3.50, says Baun. Meade's
low-end scopes use only one MCU; the high end has as many as 10.
The big capability yet small size of 8-bit MCUs also appealed to Food
Automation-Service Techniques Inc. (FAST), Stratford, CT. The maker of
commercial kitchen appliances embeds 8-bit chips into its networked kitchen
appliances, says Mario Ceste, vice president of business development.
One appliance, for example, signals when a burger is nearing tasty perfection
and automatically turns on the bun warmer.
While the cornucopia of consumer applications for 8-bit processors continues
to abound, automotive and industrial applications still account for the
lion's share of installed MCUs, says Dataquest's Starnes. Although consumer
products like VCRs ship in the millions, they typically have only one
or two MCUs. But cars, which also ship in the millions, have dozens of
MCUs. For this reason, Starnes expects automotive and other industrial
applications to continue to be the mainstay of the MCU market.
Simple, yet flashy
Today, MCUs range from one-third the size of a dime, a mere 3mm square,
to the size of a quarter. Some contain roughly the same number of components
in a single device as 20 chips 23 years ago, when the Zilog Z-80 was king
of the CP/M-based desktop computer, says Geoff Lees, marketing director
for the microcontroller business line at Philips Electronics North America
Corp., Sunnyvale, CA.
One trend driving the 8-bit market is the replacement of mask ROM with
flash memory. Because it is rewriteable, flash allows manufacturers to
program the devices right before they ship, Lees says. This means that
code bugs found late in the manufacturing stage can be fixed without wasting
It's like having field-programmable gate arrays (FPGAs) in every product,
says Meade's Baun. If the company wants to change code at the last minute
or have products that can be upgraded in the field, it can use MCUs with
flash. While flash is about 20% more expensive than mask ROM, it saves
money at the back end in fewer faulty chips, he says. If a software bug
is discovered in an MCU with one-time programmable (OTP) memory or mask
ROM, then all the chips already manufactured become trash, notes Kevin
Killbane, strategic marketing manager in Motorola's 8/16-Bit Microcontroller
Flash also speeds a product's time to market, he adds. The flexibility
of flash MCUs means that customers often do not need to create custom
chips, and therefore do not face non-recurring engineering expenses that
often come with custom silicon, he adds.
Same song, second verse
An important benefit for system designers is that they can create the
parts they need by reprogramming the flash of a single MCU model, says
Baun. "We don't need to keep lots of components in stock," he says. "Sometimes
we use exactly the same [MCUs] with slight program modifications" in different
"We put cost where the feature is," he says. The EXT90 telescope, an entry-level
telescope that sells for $150 in stores like Costco Warehouse Corp., uses
the same MCU as other, more expensive units. When a user buys a telescope
with more features, more capabilities are added to the microcontrollers'
"What makes 8-bit
MCUs so versatile is their low cost and, well, their eight bits."
-Dave Yeskey, vice president,
Microchip Technology Inc.
These simple MCUs also are getting faster. While early 8-bit MCUs were
built to support only 5- to 10-MHz frequencies, some of today's chips
can reach a whopping 100 MHz, says Max Baron, a principal analyst at In-Stat/MDR,
a market research firm in Scottsdale, AZ, which is owned by ELECTRONIC
BUSINESS ' parent company, Reed Business Information. Baron agrees that
MCUs today "essentially function as FPGAs," but are more flexible. The
programmability of gate arrays is limited, he notes, while MCUs are not
only programmable, but can include other functions such as analog-to-digital
So what does the crystal ball hold in store for 8-bit MCUs? Future chips
will offer better performance, more flash memory and require less power,
which means the chips will find more uses in handheld devices, mobile
electronics and the like, says Lees. As manufacturers move to smaller
designs, Microchip plans to move to 0.35 micron and below, says Yeskey.
When it comes to next-generation applications, 8-bit MCU vendors "are
the glue that holds it all together," he says. "That's the dichotomy of
While applications for MCUs might change as new features are added, Lees
says at least one aspect of 8-bit technology will remain the same: They
will always be cheap and easy to work with.
Stephen Lawton, a freelance writer in San Bruno, CA, is the former
editor-in-chief of MicroTimes, Digital News & Review, NetscapeWorld
and SunWorld. E-mail him at firstname.lastname@example.org.
At home with MCUs
Take a tour through your son or daughter's room, and you'll likely
encounter at least a half-dozen 8-bit MCUs.
They're in the more obvious places-the TV, VCR, DVD player, PC and
Nintendo 64 game console and controllers. They're in the Game Boy
and boom box. But they're also in the free Buzz Lightyear toy from
Burger King, the electronic Star Wars toy, an electronic keyboard,
a $2.99 Pokémon toy and a remote-control car. They're also in the
smoke and carbon-monoxide alarms on the ceiling and the electronic
dartboard on the wall.
Roam around the house. The Norelco iron has an MCU (it turns off
the heat if the iron sits for a long time or is left in a horizontal
position), and cordless and cellular telephones and digital and
film cameras all include microcontrollers. They're in the Timex
Data Link watch, which doubles as a personal digital assistant,
as well as other PDAs, such as the Palm VII.
Wander out to the garage, the Toyota Camry, like most cars built
in recent years, has dozens of 8-bit MCUs. The Ford Winstar van
has 8-bit MCUs that calculate the air pressure in the tires.
Even Fido is sporting a microcontroller. MCUs are found in some
dog collars; they're part of invisible fence systems that keep pooches
from escaping the yard. Semico Research Corp., Phoenix, estimates
that by 2006, we will run into 300 microcontrollers in various devices
every day. -S.L.