5.5.1. Editing JTAG files

To access the .jtg file editor, using Multi-ICE direct connect connection as an example:

  1. Start RealView Debugger without connecting to a target.

  2. Right-click on the ARMOAK_MICE entry in the Connection Control window to display the context menu.

  3. Select Connection Properties... to display the Connection Properties window.

  4. Right-click on the *Configuration entry in the right pane, for the required .jtg file, and select Edit Configuration-File Contents... from the context menu.

This displays the Device JTAG-File Editor dialog box. An example is shown in Figure 5.16.

Figure 5.16. Device JTAG-File Editor dialog box

Device JTAG-File Editor dialog box

Use this dialog box to amend the current device list, or to add new devices to the stored scan chain. The dialog box contains the following controls:


Enter the name of a new device to be added to the configuration. This name identifies the new processor in the Connection Control window.


Click on the down arrow to see a list of predefined processor types, for example ARM.


The choices displayed in the drop-down list are determined by the vehicle defined for this connection, as set by the Connect_with/Manufacturer (see Appendix A Configuration Settings Reference).

On Connect:

Click on the down arrow to see a list of processor reset options when making a connection to the chosen device, for example Reset.


This is used to ignore a particular TAP controller, preventing the debugger from connecting to it. Insert in the text field the number of bits in the Scan Chain Select Register (SCSR) for the bypassed device. For ARM CPUs this depends on CPU model, but is normally either 4 or 5.

The bypass option is not available for some vehicle types.


If your configuration file contains non-generic, target-specific entries, use this field to specify these parameters.

Create New

When you have entered the device details, click here to add the new device to the top of the display list.

Device List

This shows all the devices currently configured in the JTAG file. As you create a new device it is added to the top of the list.

The list is ordered as shown in Figure 5.17. That is, the top list entry corresponds to the device that has its Test Data In (TDI) connected to the host interface Test Data Out (TDO) pin and the bottom list entry has its TDO connected to the TDI pin of the host interface.

Figure 5.17. JTAG chain ordering

Move Up

Use this to change the order of entries in the display list. Highlight an entry and click Move Up to move it up towards the top of the list by one place.

Move Down

Use this to change the order of entries in the display list. Highlight an entry and click Move Down to move it down towards the bottom of the list by one place.


Click to copy an existing entry and add it to the device list.


Click to edit a device definition and so rename it in the device list. Editing a device also means that you can change the text given in the Description column in the Connection Control window.

There is a limit on the number of characters that can be displayed in the Description column.


Click to remove a highlighted entry from the device list.


Use this data field to specify the full pathname to the .jtg file that defines the device list.


Click to confirm your entries and so update the specified .jtg file. This closes the Device JTAG-File Editor dialog box.


Click to close the Device JTAG-File Editor dialog box without making any changes to the device list.


Click to get online help text about this dialog box.

Viewing changes

You must save the amended board file entries to update the contents of the Connection Control window. After confirming entries in the Device JTAG-File Editor dialog box, select File ? Save and Close to close the Connection Properties window.

If the chosen entry was expanded in the Connection Control window, saving the updated board file settings collapses the second-level entry.

Expand the entry to see the new or updated devices available for connection.

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