Rainbow Electronics MAXQ2010 - Manual (Page 30)

MAXQ2010
16-Bit Mixed-Signal Microcontroller with LCD
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engine can monitor internal activities and interact with
selected internal registers while the CPU is executing
user code. Collectively, the hardware and software fea-
tures allow two basic modes of in-circuit debugging:
• Background mode allows the host to configure and
set up the in-circuit debugger while the CPU contin-
ues to execute the application software at full speed.
Debug mode can be invoked from background mode.
• Debug mode allows the debug engine to take control
of the CPU, providing read/write access to internal reg-
isters and memory, and single-step trace operation.
Applications Information
The low-power, high-performance RISC architecture of
this device makes it an excellent fit for many portable or
battery-powered applications that require cost-effective
computing. The high-throughput core is complemented
by a 16-bit hardware multiplier-accumulator, allowing
the implementation of sophisticated computational
algorithms. Applications benefit from a wide range of
peripheral interfaces, allowing the microcontroller to
communicate with many external devices. With integrat-
ed LCD support of up to 160 segments, applications
can support complex user interfaces. Displays are dri-
ven directly with no additional external hardware
required. Contrast can be adjusted using a built-in,
adjustable resistor. The simplified architecture reduces
component count and board space, critical factors in
the design of portable systems.
The MAXQ2010 is ideally suited for applications such
as medical instrumentation, portable blood-glucose
equipment, and data-collection devices. For blood-glu-
cose measurement, the microcontroller integrates an
SPI interface that directly connects with analog front-
ends for measuring test strips.
Grounds and Bypassing
Careful PCB layout significantly minimizes noise on the
analog inputs, resulting in less noise on the digital I/O
that could cause improper operation. The use of multi-
layer boards is essential to allow the use of dedicated
power planes. The area under any digital components
should be a continuous ground plane if possible. Keep
any bypass capacitor leads short for best noise rejec-
tion and place the capacitors as close to the leads of
the devices as possible.
Separate ground areas must be provided for the analog
(AGND) and digital (DGND) portions, connected
together at a single point.
CMOS design guidelines for any semiconductor require
that no pin be taken above V
DVDD or below DGND.
Violation of this guideline can result in a hard failure
(damage to the silicon inside the device) or a soft failure
(unintentional modification of memory contents). Voltage
spikes above or below the device’s absolute maximum
ratings can potentially cause a devastating IC latchup.
Microcontrollers commonly experience negative volt-
age spikes through either their power pins or general-
purpose I/O pins. Negative voltage spikes on power
pins are especially problematic as they directly couple
to the internal power buses. Devices such as keypads
can conduct electrostatic discharges directly into the
microcontroller and seriously damage the device.
System designers must protect components against
these transients that can corrupt system memory.
Additional Documentation
Designers must have four documents to fully use all the
features of this device. This data sheet contains pin
descriptions, feature overviews, and electrical specifi-
cations. Errata sheets contain deviations from pub-
lished specifications. The user’s guides offer detailed
information about device features and operation. The
following documents can be downloaded from
www.maxim-ic.com/microcontrollers .
• This MAXQ2010 data sheet, which contains electri-
cal/timing specifications and pin descriptions.
• The MAXQ2010 revision-specific errata sheet
( www.maxim-ic.com/errata ).
• The MAXQ Family User's Guide , which contains detailed
information on core features and operation, including
programming (
www.maxim-ic.com/MAXQUG ).
• The MAXQ Family User's Guide: MAXQ2010 Supplement ,
which contains detailed information on features spe-
cific to the MAXQ2010.
Development and Technical
Support
Maxim and third-party suppliers provide a variety of
highly versatile, affordably priced development tools for
this microcontroller, including the following:
• Compilers
• In-circuit emulators
• Integrated Development Environments (IDEs)
• JTAG-to-serial converters for programming and
debugging
A partial list of development tool vendors can be found
at
www.maxim-ic.com/MAXQ_tools .
For technical support, go to www.maxim-ic.com/support .