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
Follow the below list 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.