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 VDDS0)
- Connection of the required pulls as per the pin connectivity requirements near to the processor JTAG pins
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 VDDS0)
- 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 required, the TRC_DATAn signals are required to be connected to the emulation connector. All TRC_DATAn signals are pin-muxed with other signals. If the trace connections are implemented, 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 can affect the custom board functions