Nuts & Volts

supplies the programming interface
to the LPC2106’s on-chip Flash
program memory.
The LPC2106 is big on memory
and speed. So, you would expect it to
also be big on peripherals. Many
of the eight-bit microcontrollers
multiplex the serial interfaces. In
that this is a Philips microcontroller,
and Philips invented I 2 C, you can be
sure that a dedicated and by-thebook-fully-functional
I 2 C hardware interface
is provided on
the LPC2106. As
Figure 1 shows us,
the LPC2106’s dedicated
I 2 C interface
logically leaves room
for a dedicated SPI
serial interface.
Everything else
that you would normally
associate with
any eight-bit microcontroller
can also be
found as a feature of
the LPC2106. The
LPC2106 microcontroller
build includes
a pair of UARTS
and timers with capture/compare
capability,
a six-channel
PWM subsystem, a
real time clock, a
watchdog timer, and a
really neat vectored
interrupt controller.
Note the absence
of analog-to-digital
conversion circuitry
on the LPC2106.
Electronic
devices require some
sort of power source
to operate and the
LPC2106 is no exception.
The LPC2106
thus far has been big
■ FIGURE 1. Getting a
handle on the LPC2106
isn’t so bad once you
break it down into
its component parts.
Before we’re done with
this device, we’ll touch
on most everything you
see in the figure.
on everything. As you would expect,
the LPC2106 has big power needs,
too. However, don’t confuse big for
bad here. The normal eight-bit microcontroller
runs on a single voltage
rail. The LPC2106 requires a pair of
separate power levels. The LPC2106
CPU core feeds from a +1.8 VDC
power source, while the LPC2106’s
I/O subsystems need a +3.3 VDC
power rail.
THE DESIGN CYCLE
The LPC2106’s “big” power
requirement is in the number of
required power rails only and in
unison with the pair of LPC2106 low
power modes allows the LPC2106 to
operate efficiently at very low power
consumption levels. The LPC2106
also interoperates easily with legacy
+5 VDC systems as most of its I/O
pins are five volt tolerant.
Okay, now we have a pretty good
April 2006 87