Rainbow Electronics MAXQ613 - Manual (Page 27)

16-Bit Microcontroller with Infrared Module
MAXQ613
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Applications Information
The low-power, high-performance RISC architecture of
this device makes it an excellent fit for many portable
or battery-powered applications. It is ideally suited for
applications such as universal remote controls that
require the cost-effective integration of IR transmit/
receive capability.
Grounds and Bypassing
Careful PCB layout significantly minimizes system-level
digital noise that could interact with the microcontroller
or peripheral components. The use of multilayer boards
is essential to allow the use of dedicated power planes.
The area under any digital components should be a con-
tinuous ground plane if possible. Keep bypass capacitor
leads short for best noise rejection and place the capaci-
tors as close to the leads of the devices as possible.
CMOS design guidelines for any semiconductor require
that no pin be taken above V
DD or below GND. Violation
of this guideline can result in a hard failure (damage to
the silicon inside the device) or a soft failure (uninten-
tional 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 micro-
controller and seriously damage the device. System
designers must protect components against these tran-
sients that can corrupt system memory.
Additional Documentation
Designers must have the following documents to fully
use all the features of this device. This data sheet
contains pin descriptions, feature overviews, and elec-
trical specifications. Errata sheets contain deviations
from published specifications. The user’s guides offer
detailed information about device features and opera-
tion. The following documents can be downloaded from
www.maxim-ic.com/microcontrollers .
• This MAXQ613 data sheet, which contains electrical/
timing specifications, pin descriptions, and package
information.
• The MAXQ613 revision-specific errata sheet
( www.maxim-ic.com/errata ).
• The MAXQ610 User’s Guide, which contains detailed
information on features and operation, including pro-
gramming.
Table 6. Stop Mode Power-Fail Detection States with Power-Fail Monitor Disabled
(continued)
STATE POWER-FAIL
INTERNAL
REGULATOR
CRYSTAL
OSCILLATOR
SRAM
RETENTION
COMMENTS
D Off Off Off Yes
Application enters stop mode.
V
DD > V RST .
CPU in stop mode.
E
On
(Periodically)
Off Off Yes
V POR < V DD < V RST .
An interrupt occurs that causes the CPU to
exit stop mode.
Power-fail monitor is turned on, detects a
power-fail, and puts CPU in reset.
Power-fail monitor is turned on periodically.
F Off Off Off —
V
DD
< V
POR
.
Device held in reset. No operation allowed.