JTAG Chain Description

The JTAG chain description (in the project file preamble) tells XJEase where the TDI and TDO are on the board (i.e. where the chain begins and ends).

The JTAG CHAIN section also contains the CONNECTOR section, which defines how the pins on the XJLink are connected to the target board. The pin mapping may be one of the supported standard connectors or a user defined pin mapping.

From this information, the system can search the netlist to find all the boundary scan devices on the JTAG chain and identify the order in which they occur.

Syntax

JTAG CHAIN
    CONNECTOR ConnectorName
        TDI := boardName.reference.pin ;
        TDO := boardName.reference.pin ;

        // Pin mapping
        [
          PINMAP "filename" ;
          |
          MAPPING ... END ;
          // Optionally specify a Test Reset sequence
          { SEQUENCES ... END ; }
        ]

    END;

    // TCK frequency
    { FREQUENCY := integer [ M | K ] ; }

    // Disable automatic idcode checks
    { IDCODE_CHECK := FALSE ; }

    // Disable auto skew
    { AUTOSKEW := FALSE ; }

    // Override skew values
    {
      AUTOSKEW
        SUBCHAIN [ DEFAULT | "subchain" ]
          { frequency [ M | K ] := value; }
          ...
        END;
        ...
      END;
    }

    // Profile list
    {
      PROFILES
        {
          PROFILE "name" { , DEFAULT }
            SUBCHAINS
              { "subchain" { := [ "reset" | DEFAULT ] } ; }
              ...
            END;
          END;
        }
        ...
      END;
    }

    // Subchain list
    {
      SUBCHAINS
        {
          SUBCHAIN "name"
            TDI := tdi { , ... } ;
            DEVICES
              { boardName.reference }
              ...
            END;
          END;
        }
        ...
      END;
    }
END;