maxq3212-emx+ Maxim Integrated Products, Inc., maxq3212-emx+ Datasheet - Page 21

• Manufacturer Part Number: maxq3212-emx+
• Description: Maxq3212 Microcontroller With Analog Comparator And Led Driver
• Manufacturer: Maxim Integrated Products, Inc.

Embedded debugging capability is available through
the JTAG-compatible Test Access Port. Embedded
debug hardware and embedded ROM firmware pro-
vide in-circuit debugging capability to the user applica-
tion, eliminating the need for an expensive in-circuit
emulator. Figure 5 shows a block diagram of the in-cir-
cuit debugger. The in-circuit debug features include:
• Hardware debug engine
• Set of registers able to set breakpoints on register,
• Set of debug service routines stored in the utility
The embedded hardware debug engine is an indepen-
dent hardware block in the microcontroller. The debug
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
• Debug mode allows the debug engine to take con-
Figure 5. In-Circuit Debugger
TMS
TCK
TDO
TDI
code, or data accesses
ROM
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 back-
ground mode.
trol of the CPU, providing read/write access to inter-
nal registers and memory, and single-step trace
operation.
MAXQ3212
CONTROLLER
TAP
Microcontroller with Analog Comparator
(UTILITY ROM)
BREAKPOINT
ROUTINES
In-Circuit Debug
SERVICE
ENGINE
DEBUG
DEBUG
CONTROL
ADDRESS
DATA
____________________________________________________________________
CPU
Careful PC board layout significantly minimizes crosstalk
among the reference input, comparator outputs, and dig-
ital inputs. Keep digital and analog lines separate, and
use ground traces as shields between them where pos-
sible. Separate CMPI and V
ning a ground trace between these pins. Bypass V
with a capacitor as low as 1µF and keep bypass capaci-
tor leads short for best noise rejection.
The low-power, high-performance RISC architecture of
the MAXQ3212 makes it an excellent fit for many
portable or battery-powered applications that require
cost-effective computing. The analog comparator can
function as an analog-to-digital converter (ADC) when
simple analog measurements are necessary, and the
high-current I/O pin can drive a power or status LED.
This device can also be used as a low-cost ADC. The
single-slope conversion method can be easily imple-
mented using the internal comparator and an internal
timer. The basic implementation of such a converter is
illustrated below. One of the benefits of this approach is
the small number of external components required: the
transistor creates a constant current source, a ramp
capacitor times the conversion, and a resistor and
capacitor on the comparator input acting as a simple
filter. The result is the addition of A/D capability to the
end system at virtually no additional cost.
Applications Information
and LED Driver
Grounds and Bypassing
REF
from each other by run-
Applications
DD
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