GET_JTAG_CHAINS

The GET_JTAG_CHAINS function returns STRING device references for every JTAG device currently available on every JTAG chain. When run from a test of a dynamic chains project it will return all JTAG devices associated with the profile of that test. In a subchain reset sequence it will return just those that make up the subchain. When run in a non-dynamic project it will always return all JTAG devices defined in the project.

GET_JTAG_CHAINS( )

Examples using an XJLink2 (that supports up to 4 JTAG chains) and the XJDemo board

Printing the JTAG devices using FOREACH loops when running inside the 'All chains' profile:

  LOCAL PrintJtagDevices()()
    STRING[][] jtagChains := GET_JTAG_CHAINS();
    
    FOREACH STRING[] chain IN jtagChains
      FOREACH STRING deviceRef IN chain
        PRINT(deviceRef, "\n");
      END;
    END;
  END;

Output

U1
U2

Printing the contents of every chain array returned:

LOCAL PrintAllJtagChains()()
  INT chainNumber := 1;
  STRING[][] jtagChains := GET_JTAG_CHAINS();
  
  FOREACH STRING[] chain IN jtagChains
    PRINT("Chain ", chainNumber, ". JTAG device count: ", WIDTHOF(chain), ". JTAG device references: ");
    FOREACH STRING deviceRef IN chain
      PRINT(deviceRef, ", ");
    END;
    PRINT("\n");
    chainNumber := chainNumber + 1;
  END;
END;

Output

Chain 1. JTAG device count: 1. JTAG device references: U1, 
Chain 2. JTAG device count: 1. JTAG device references: U2, 
Chain 3. JTAG device count: 0. JTAG device references: 
Chain 4. JTAG device count: 0. JTAG device references: 

JTAG device references returned by GET_JTAG_CHAINS are always unique and guaranteed to work with built-in functions that take JTAG or non-JTAG device references.

The indexes of JTAG chains and the indexes of JTAG device references within those chains are off-by-one when compared to the values used by GET_JTAG_DEVICE and GET_JTAG_DEVICE_COUNT. This is because GET_JTAG_DEVICE and GET_JTAG_DEVICE_COUNT use 1-based positions whereas GET_JTAG_CHAINS uses 0-based arrays.