1.1. Debug and Trace Connectors

This specification provides a small, optional extension to connectors described in MIPI Debug & Trace Connectors Recommendations White Paper, Version 1.20, 2 July 2021.

These optional extensions are as follows:

  • Clarifying dual voltage debug and trace via Mictor 38 connector (re-defining obsolete pin #14).

  • Allowing MIPI20 TRC_DATA[2] and TRC_DATA[3] to be optionally used as TRIGIN/TRIGOUT pins.

  • Defining some signal as (optional) serial trace and/or application UART.

MIPI Alliance positively reviewed proposals for above optional extensions and hopefully will adopt them in the future.

Additionally, the following MIPI20 signals are clarified as follows:

  • MIPI20 pin#12 RTCK signal is not applicable to RISC-V. If the target is not providing a parallel trace, the target connector must provide GND on this pin. If parallel trace is used, pin#12 must be used as a TRC_CLK signal.

  • MIPI20 pin#14 nTRST_PD signal is not applicable for RISC-V. If nTRST is really needed, pin#16 nTRST should be used.

Above two signals were present in older RISC-V Debug Specification but were never implemented/used.

This specification also adds the following option (described in dedicated chapter):

  • Defining MIPI20 pins #11 and #13 as optional TgtPwr+Cap pins (to supply 5V to power-up a small, evaluation target board). This option is already supported by several debug and trace probe vendors.