General
Review and verify the following for
the custom schematic design:
- Above sections, including
relevant application notes and FAQ links
- Pin attributes, signal
descriptions, and electrical specifications
- Electrical characteristics,
timing parameters, and any additional available information
- JTAG signals IO compatibility
(IO supply referenced to VDDSHV_MCU)
- Connection of the required
pulls as per the pin connectivity requirements near to the processor JTAG
signals
Schematic Review
Have you followed the below for the
custom schematic design:
- Connection of supply voltage
to the JTAG connector including filter capacitor (connect the voltage source
that connects to VDDSHV_MCU)
- Pullup and pulldown values
(use 47kΩ or 10kΩ)
Additional
- TI recommends that all custom board designs contain at least a minimal JTAG port
connection to test points or header for early prototype debugging. The minimum
connections are TCK, TMS, TDI, TDO and TRSTn. If desired, delete JTAG routes and
component footprints (except the pulldown on TRSTn and the pullups on TMS and
TCK) in the production version of the board
- Provision to configure EMU0 and EMU1 signals is recommended
- If trace operation is needed, the
TRC_DATAn signals must connect to the emulation connector. All TRC_DATAn signals
are pin-muxed with other signals. If the trace connections are needed, do not
use other muxed interfaces on the pins. Use short and shew matched routes for
TRC_DATAn signals. Trace signals are on a separate power domain and can be at a
different voltage from the other JTAG signals
- Provision for external ESD protection. Populate when JTAG interface is used
- Verify fail-safe operation when connected to external signals. Applying an
external input before supply ramps can cause voltage feed and affect the
processor performance