Datasheet

MAX31782
System Management Microcontroller
18
In-Circuit Debug
Embedded debugging capability is available through
the JTAG-compatible test access port (TAP). Embedded
debug hardware and embedded ROM firmware provide
in-circuit debugging capability to the user application,
eliminating the need for an expensive in-circuit emulator.
Figure 6 shows a block diagram of the in-circuit debug-
ger. The in-circuit debug features include the following:
• Hardwaredebugengine
• Set of registers able to set breakpoints on register,
code, or data accesses (ICDA, ICDB, ICDC, ICDD,
ICDF, ICDT0, and ICDT1)
• SetofdebugserviceroutinesstoredintheutilityROM
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
features allow two basic modes of in-circuit debugging:
background and debug.
Background mode allows the host to configure and set
up the in-circuit debugger while the CPU continues 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 regis-
ters and memory, and single-step trace operation.
Applications Information
Power-Supply Decoupling
To achieve the best results when using the device,
decouple the V
DD
power supply with a 0.1FF capacitor.
Use a high-quality, ceramic, surface-mount capacitor
if possible. Surface-mount components minimize lead
inductance, which improves performance, and ceram-
ic capacitors tend to have adequate high-frequency
response for decoupling applications.
Decouple REG25 and REG18 using 1FF and 10nF
capacitors (one each per output). Note: Do not use
either of these pins for external circuitry.
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 specifica-
tions. Errata sheets contain deviations from published
specifications. The user’s guides offer detailed information
about device features and operation. The following docu-
ments can be downloaded from www.maxim-ic.com.
• TheMAX31782datasheet,whichcontainselectrical/
timing specifications and pin descriptions.
• The MAX31782 revision-specific errata sheet
(www.maxim-ic.com/errata).
• TheMAX31782 User’s Guide, which contains detailed
information on core features and operation, including
programming.
___________________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(Candassembly)
• In-circuitdebugger
• Integrateddevelopmentenvironments(IDEs)
• Serial-to-JTAG converters for programming and
debugging
• USB-to-JTAG converters for programming and
debugging
Technical support is available through email at
[e-mail].
Figure 6. In-Circuit Debugger
TAP
CONTROLLER
CPU
DEBUG
ENGINE
DEBUG
SERVICE
ROUTINES
(UTILITY ROM)
CONTROL
BREAKPOINT
ADDRESS
DATA
MAX31782
TMS
TCK
TDI
TDO