Microcontrollers vs. microprocessors: What’s the difference?

Microcontroller
units
(MCUs)
and

microprocessor
units
(MPUs)
are
two
kinds
of
integrated
circuits
that,
while
similar
in
certain
ways,
are
very
different
in
many
others.
Replacing
antiquated
multi-component

central
processing
units
(CPUs)
with
separate
logic
units,
these
single-chip
processors
are
both
extremely
valuable
in
the
continued
development
of
computing
technology.
However,
microcontrollers
and
microprocessors
differ
significantly
in
component
structure,
chip
architecture,
performance
capabilities
and
application.

The
key
difference
between
these
two
units
is
that
microcontrollers
combine
all
the
necessary
elements
of
a
microcomputer
system
onto
a
single
piece
of
hardware.
Microcontrollers
do
not
require
additional
peripherals
or
complex
operating
systems
to
function,
while
microprocessors
do.
Both
circuits
contain
CPUs,
however,
microcontrollers
also
integrate

memory,
input/output
(I/O)
components
and
other
varied
peripherals. 

Cost-effective
and
small-in-size,
low-power
microcontrollers
are
optimized
for
all-in-one
functionality.
As
a
result,
these
units
are
best
used
for
specific
applications
like
automotive
infotainment
systems
and

Internet-of-Things
(IoT)
devices.

Conversely,
general-purpose
microprocessors
are
typically
more
powerful
and
are
designed
to
be
supported
by
specialized
hardware
for
increased
performance
in
demanding
applications
like
personal
computing
and
graphics
processing. 

On
a
hardware
level,
microprocessors
are
based
on
the
“classical”
von
Neumann
architecture.
This
consists
of
a
CPU
with
both
an
arithmetic
logic
unit
(ALU)
and
processor
registers
(small
amounts
of
fast
memory
storage
for
quick
data
access),
a
control
unit,
memory
for
data
and
instructions,
external
memory
for
mass
storage,
and
I/O
mechanisms.
This
methodology
uses
the
same
set
of
interconnecting
wires
(known
as
a
bus)
to
both
transmit
instructions
and
perform
operations.
Microprocessors
cannot
perform
these
actions
simultaneously,
yet
modern
devices
use
various
mitigation
techniques
to
avoid
data
bottlenecks.

On
the
other
hand,
microcontrollers
use
the
more
complex
Harvard
architecture,
which
has
one
dedicated
set
of
data
buses
and
address
buses
for
reading
and
writing
data
to
memory,
and
another
set
to
fetch
instructions
for
performing
operations.
Since
the
CPU
can
both
read
an
instruction
and
access
data
memory
at
the
same
time,
the
Harvard
architecture
can
perform
basic
operations
faster.

The
Harvard
architecture
excels
at
real-time
and
high-speed
computing
tasks.
However,
the
unified
data
and
instructions
memory
space
of
the
simplified
von
Neumann
architecture
results
in
improved
reliability
and
scalability.
For
this
reason,
von
Neumann-based
microprocessors
are
favored
for
more
demanding
tasks
such
as

high-performance
computing
(HPC)
and
gaming,
while
microcontrollers
are
typically
used
to
handle
fast
signal
processing. 

Key
differences
between
microcontrollers
and
microprocessors

When
comparing
microcontrollers
and
microprocessors,
it’s
helpful
to
consider
four
key
features:

Features	Microcontrollers	Microprocessors
Integrations	Microcontrollers integrate CPU, memory and I/O ports onto a single chip.	Microprocessors require external components such as memory and additional peripherals.
Applications	Microcontrollers are better suited for specific, low-power or ultra-low power applications within embedded systems, such as home appliances like washing machines or IoT devices.	Microprocessors are more suitable for general-purpose and high-performance applications requiring more processing power, such as personal computers or the types of servers used in data centers.
Performance	Microcontrollers are optimized for efficiency and real-time processing and operate at lower clock speeds up to 200 MHz.	Microprocessors are built for more demanding and complicated computations and can operate at clock speeds above 1 GHz.
Cost	Microcontroller hardware is generally inexpensive and because they do not require specialized programming knowledge, they add very little to overall project budgets.	Microcontrollers are better suited for specific, low-power or ultra-low-power applications within embedded systems, such as home appliances like washing machines or IoT devices.

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Understanding
microcontrollers

Essentially,
a
microcontroller
is
a
small
computer
on
a
single
chip,
containing
a
processor
core
(or
cores),
operational
memory
(RAM)
and
electrically
erasable
programmable
read-only
memory
(EEPROM)
for
program
memory.
Optimized
to
function
as
standalone
units,
microcontroller
integrations
improve
real-time
signal
processing
and
make
these
compact
units
ideal
for
controlling
specific
tasks
or
duties
within
embedded
systems.

Key
components
of
a
microcontroller

• 
  Central
  processing
  unit
  
  (CPU):
  Colloquially
  referred
  to
  as
  the
  computer’s
  “brain,”
  the
  CPU
  is
  responsible
  for
  executing
  instructions
  and
  controlling
  operations.  
• 
  Memory:
  Microcontrollers
  contain
  both
  volatile
  memory
  (RAM),
  which
  stores
  temporary
  data
  that
  may
  be
  lost
  if
  the
  system
  loses
  power,
  and
  non-volatile
  flash
  memory
  (ROM)
  for
  storing
  the
  microcontroller’s
  programming
  code.
• 
  Peripherals:
  Depending
  on
  the
  intended
  application,
  a
  microcontroller
  may
  contain
  various
  peripheral
  components,
  such
  as
  I/O
  interfaces,
  timers,
  counters,
  analog-to-digital
  converters
  (ADCs)
  and
  communication
  protocols
  (UART,
  SPI,
  I2C).

Lightweight,
small
and
requiring
comparatively
low
power,
microcontrollers
are
ideal
for
battery-operated
electronic
devices
like
smartphones,
smartwatches
and
other
wearables.
They
are
also
a
favorite
among
hobbyists.
Consumer-grade
programmable
microcontrollers,
such
as
those
made
by
Arduino
or
the
Raspberry
Pi,
can
be
easily
configured
in
programming
languages
like
C,
C++
and
Python,
commonly
used
across
Windows,
Linux
and
MacOS
operating
systems. 
While
accessible
to
even
beginner
developers,
microcontrollers
are
also
frequently
applied
in
a
wide
range
of
professional
and
industrial
use
cases,
including
industrial
automation,
transportation
safety
systems
and
prototyping.   

Microcontroller
types
and
use-cases 

Responding
to
a
custom
chip
request
from
a
Japanese
calculator
manufacturer,
Texas
Instruments
engineers
Gary
Boone
and
Michael
Cochran
are
credited
with
creating
the
first
microcontroller
in
1971.
A
breakthrough
in
circuitry
technology,
the
following
years
have
produced
myriad
improvements
and
iterations
from
manufacturers
like
Intel,
NXP
and
Arm. 

The
following
are
some
of
the
more
common
types
of
microcontrollers:

• 
  8-bit
  microcontrollers:
  The
  most
  basic
  type
  of
  microcontroller
  features
  limited
  processing
  and
  memory
  and
  typically
  used
  in
  small
  appliances,
  such
  as
  toys
  and
  remote
  controls.
• 
  16-bit
  microcontrollers:
  Twice
  as
  capable
  as
  8-bit
  models,
  16-bit
  microcontrollers
  are
  used
  for
  more
  complex
  applications,
  including
  medical
  devices,
  automotive
  systems
  and
  industrial
  control
  systems.
• 
  32-bit
  microcontrollers:
  The
  most
  powerful
  and
  feature-rich
  type
  of
  microcontrollers,
  these
  are
  used
  for
  demanding
  applications,
  such
  as
  gaming
  consoles,
  entertainment
  devices
  and
  high-end
  industrial
  automation. 
• 
  Reduced
  instruction
  set
  computer
  (RISC)
  microcontrollers:
  RISC
  microcontrollers
  incorporate
  a
  design
  architecture
  that
  simplifies
  and
  improves
  operations
  by
  executing
  fewer
  compute
  instructions
  faster
  than
  other
  methodologies,
  such
  as
  the
  complex
  instruction
  set
  computer
  (CISC)
  architecture. 
• 
  ARM
  
  microcontrollers:
  Formerly
  an
  acronym
  for
  Advanced
  RISC
  Machines,
  these
  types
  of
  microcontrollers
  incorporate
  the
  ARM
  architecture,
  including
  the
  modern
  Arm
  Cortex
  subset,
  that
  bolster
  performance
  and
  reliability.
  Arm
  microcontrollers
  are
  widely
  used
  in
  mobile
  devices,
  automotive
  systems
  and
  industrial
  control
  systems.
• 
  PIC
  Microcontrollers:
  Developed
  by
  Microchip
  Technology,
  the
  PIC
  Microcontroller
  is
  the
  world’s
  smallest
  microcontroller,
  and
  it
  is
  found
  frequently
  in
  robotics,
  home
  and
  industrial
  automation
  and
  renewable
  energy
  systems.
• 
  FPGA-based
  microcontrollers:
  Commonly
  used
  in
  applications
  necessitating
  digital
  signal
  processing,
  video
  processing
  and
  high-speed
  networking,
  these
  microcontrollers
  use
  customizable
  chips
  called
  
  field-programmable
  gate
  arrays
  (FPGAs),
  which
  can
  be
  configured
  and
  reconfigured
  on
  the
  hardware
  level
  to
  create
  unique
  hardware
  solutions
  for
  demanding
  processing
  requirements.
   

Understanding
microprocessors 

Microprocessors
are
the
predominant
type
of
computer
processor,
integrating
all
the
required
components
of
a
CPU
into
a
single
circuit.
MPUs
combine
the
arithmetic,
logic
and
control
units
of
antiquated
CPU
computer
systems
into
a
single
multipurpose,
clock-driven
and
register-based
piece
of
hardware.
This
integrated
design
improves
reliability
by
reducing
potential
points
of
failure.
While
microprocessors
do
not
contain
on-chip
program
memory,
they
are
optimized
for
demanding
general-purpose
use
and
designed
to
support
and
be
supported
by
specialized
computer
peripherals.  

Key
components
of
a
microprocessor

Modern
microprocessors
combine
millions
of
small
transistors,
resistors
and
diodes
assembled
on
a
semiconductor
material
to
create
the
key
components
of
a
CPU. 

• 
  Arithmetic
  logic
  unit
  (ALU):
  The
  main
  logic
  unit
  of
  the
  CPU,
  this
  component
  executes
  logical
  operations
  including
  mathematical
  calculations
  and
  data
  comparisons. 
• 
  Control
  unit
  (CU):
  The
  CU
  circuit
  interprets
  instructions
  and
  initiates
  their
  execution,
  directing
  the
  basic
  operations
  of
  the
  processor. 
• 
  Registers:
  Small,
  fast
  memory
  storage
  used
  by
  a
  CPU
  to
  temporarily
  hold
  data
  and
  instructions
  during
  computational
  processes. 
• 
  Cache
  memory:
  Microprocessors
  and
  CPUs
  use
  cache
  memory,
  a
  high-speed
  form
  of
  memory
  located
  close
  to
  the
  CPU,
  to
  store
  frequently
  accessed
  data
  to
  accelerate
  performance. 
• 
  Processor
  cores:
  Individual
  processing
  units
  within
  microprocessors
  are
  known
  as
  cores.
  Modern
  processors
  frequently
  incorporate
  multiple
  cores
  (dual-core,
  quad-core)
  allowing
  for
  parallel
  processing
  by
  enabling
  the
  performance
  of
  multiple
  tasks
  simultaneously.   
• 
  I/O
  modules:
  A
  microprocessor’s
  I/O
  components
  are
  critical
  for
  managing
  the
  flow
  of
  data
  to
  and
  from
  the
  CPU,
  including
  any
  additional
  computer
  peripherals
  including
  networking
  peripherals
  such
  as
  ethernet
  ports
  or
  WiFi
  units.

Microprocessor
types
and
use-cases 

Versatile
microprocessors
can
be
found
in
a
wide
variety
of
applications,
while
specialized
units
are
commonly
employed
for
specific
tasks
requiring
high-power
processing.
Ranging
in
power,
performance,
size,
energy
consumption
and
many
other
aspects,
the
following
are
some
of
the
main
types
of
microprocessors:

• 
  General-purpose
  
  microprocessors:
  These
  versatile
  microprocessors
  are
  found
  in
  a
  wide
  range
  of
  common
  applications
  and
  devices,
  such
  as
  laptops
  and
  servers. 
• 
  Digital
  signal
  
  processors
  (DSPs):
  DSPs
  are
  specialized
  for
  high-speed
  numeric
  calculations
  and
  are
  often
  used
  for
  demanding
  tasks
  like
  audio
  processing,
  telecommunications
  and
  image
  processing.
  They
  may
  also
  be
  found
  in
  applications
  requiring
  the
  interpretation
  of
  analog
  to
  digital
  signals,
  such
  as
  weather
  sensors.
  DSPs
  are
  commonly
  used
  in
  military
  applications
  like
  surveillance
  drones
  and
  other
  autonomous
  aircraft.
• 
  Application-specific
  integrated
  circuits
  (ASICs):
  ASIC
  microprocessors
  are
  designed
  for
  specific
  tasks
  and
  are
  customized
  to
  meet
  the
  specific
  demands
  of
  various
  applications.
  Some
  examples
  of
  ASIC
  microprocessors
  include
  custom
  chips
  for
  game
  consoles
  or
  cryptocurrency
  mining.
  DSPs,
  GPUs
  and
  other
  types
  of
  specialized
  microprocessors
  are
  technically
  ASICs,
  as
  well.  
• 
  Graphics
  processing
  units
  (GPUs):
  
  GPU
  microprocessors
  are
  specially
  designed
  for
  the
  demanding
  task
  of
  rendering
  digital
  video
  and
  graphics
  requiring
  high-powered
  performance
  and
  parallel
  processing.
  Critically
  important
  for
  high-end
  gaming,
  powerful
  GPU
  microprocessors
  are
  also
  commonly
  used
  in
  cryptocurrency
  mining
  and
  are
  known
  for
  high
  power
  consumption. 
• 
  Network
  processors:
  A
  type
  of
  ASIC
  microprocessor
  specifically
  optimized
  for
  processing
  network
  data
  packets
  most
  frequently
  used
  in
  telecom
  switches,
  routers
  and
  network
  security
  devices. 
• 
  Coprocessors:
  Coprocessors,
  such
  as
  floating-point
  units
  (FPUs),
  are
  designed
  to
  provide
  auxiliary
  support
  for
  a
  system’s
  main
  CPU
  to
  boost
  performance
  during
  certain
  demanding
  tasks
  such
  as
  carrying
  out
  advanced
  scientific
  calculations
  or
  complicated
  mathematical
  formulas.

Choosing
between
a
microcontroller
and
microprocessor

Microcontrollers
and
microprocessors
are
capable
of
performing
some
of
the
same
tasks.
However,
depending
on
application
requirements,
each
has
their
own
unique
strengths
and
weaknesses.
The
integrated
features
of
a
microcontroller,
including
power-saving
modes
for
low
power
consumption,
make
it
ideal
for
most
embedded
systems. 

However,
in
circumstances
requiring
complex
computations
or
higher
processing
power,
microprocessors
are
a
better
choice,
but
the
added
performance
and
flexibility
come
at
the
cost
of
higher
power
consumption,
and
a
higher
price
tag.
These
features
make
microprocessors
a
go-to
for
personal
computers
and
industrial
supercomputers.

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