Debug Working Group*

* Formerly known as Test & Debug Working Group


  • Enable best system debug support in all stages of the mobile equipment development focusing on the following:
    • Low cost solutions
    • Interoperability by defining standards
    • Hardware and software interfaces and protocols interacting with or supporting system debug
  • The standardization shall supply benefits for manufacturers as well as for users. The WG will:
    • Identify the gaps in current non-MIPI and MIPI standards
    • Develop recommendations and propose solutions, which may end up in guidelines for standards as well as in interface and protocol standardizations
  • To reach the goal the WG will cooperate with other MIPI Working Groups (WG’s), and other industry bodies if appropriate.


The scope of Debug will be to unify/define:

  • Mating connection and pin assignment for debug and test tooling
  • Electrical/timing characteristics of these interfaces
  • Common base protocols/carrier protocol
  • A system-wide debug approach

MIPI Debug standards/recommendations completed 

  • Parallel Trace Interface
  • Debug Connectors
  • Trace Wrapper Protocol
  • System Trace Protocol
  • Narrow I/F for Debug and Trace (NIDnT)

Debug has many different efforts underway

  • Gigabit Debug
    • SneakPeek Protocol
    • Gibabit Trace Framework
    • Gigabit Debug Adapters
      • USB
      • TCP/UDP
The current focus of the Debug Working Group is a shift away from dedicated debug/trace links to standard network links. This requires profound changes in the on chip debug infrastructure: 
  • A new debug protocol (SneakPeek)
  • A framework conveying high bandwidth trace data using the existing TWP (Gigabit Trace).
The Gigabit Debug Adapters focus on mapping the network independent SneakPeek Protocol and Gigabit Trace Framework to networks such as USB, TCP, UDP.


  • Spun off minimum-pin debug effort to IEEE 1149.7 (2006)
  • System Trace Protocol Specification (2007)
    • Generic trace protocol optimized for efficient transport of HW and SW trace messages
  • Parallel Trace Interface Specification (2007)
    • Timing and electrical specification for parallel trace interface
  • Debug Connectors Recommendation (2008)
    • Connector types and pin mappings
  • Open System Trace Base Protocol Specification (2009)
    • Low level protocol for SW message trace
  • System Trace Protocol Specification 2.0 (2010)
    • Expands on 1.0 with increased channel/master space, better synchronization, and enhanced timestamps
  • Trace Wrapper Protocol Specification (2010)
    • Defines how to merge data from multiple trace sourced into a single stream  
  • Parallel Trace Interface Specification 2.0 (2011)
    • Adds multi-drop trace
  • Debug Connectors Recommendation 1.1 (2011)
    • Connector types and pin mappings
  • Specification for Narrow Interface for Debug and Test (2013)
    • Reuse of microSD Interface for Debug


  • Architecture Overview for Debug (2014)
    • Overview document that pulls together all the efforts in MIPI Debug
  • Sneak Peek (2014)
    • Communication protocol between a mobile terminal and external equipment for Debug via a standard network link
  • Gigabit Trace (2014)
    • A network independent methodology for transporting trace data over high speed functional interfaces using the existing Trace Wrapper Protocol 
  • Gigabit Debug Adapters (2014)
    • Defines the specifics of adapting the Gigabit Trace Framework and the SneakPeek Protocol to USB, TCP and UDP. 

Working Group Chair

Enrico Carrieri, Intel Corporation


Working Group Vice-Chair

Jean-Francis Duret, STMicrelectronics

MIPI_TDWG_whitepaper_NIDnT_V1_0.pdf443.58 KB
mipi_TDC_recommendation_v1_10_00.pdf544.29 KB
MIPI_TDWG_whitepaper_V3_2.pdf584.66 KB
mipi-wp-cjtag-v1_42.pdf157.25 KB