Subchains Panel

The Subchains Panel found in the Advanced Configuration Options tab shows the current set of Subchains in the project.

JTAG subchains

This section is visible when subchains are defined that include JTAG devices.

Auto

This column is only visible when Automatic Configuration is enabled. Subchains generated automatically by the system will have a tick. Being automatically generated means these subchains will track any future project changes to the number of JTAG devices included in the TAP group.

Name

The name of the subchain used when configuring profiles and reset sequences.

TAP Group

The TAP group this subchain is made from or (None).

Devices

The JTAG devices held in the subchain.

External Hardware

Any external hardware included in the subchain.

Target TCK

This column is only visible when Optimised Scans is enabled. Target TCK is the TCK frequency all JTAG chains included in the subchain will target. A target TCK frequency is not a guarantee it will run at that exact speed. Rather it is only guaranteed it will not exceed it. It may run slower due to other factors in the project setup or the type of XJLink hardware used at runtime. The default frequency is the lowest TCK frequency found in the BSDL files of the JTAG devices included in the subchain. The frequency can be modified inline by double-clicking in the TCK frequency cell and in the Add/Edit Subchain dialog. A reset button is also visible when editing the value. This is enabled if the value is not the default, and clicking it will set it back to the default for the subchain.

Available Reset Sequences

This lists all Subchain Reset Sequences associated with the subchain. A built-in sequence is always included as an option. When there is more than one reset sequence associated with a subchain, the sequence to use is determined per profile in the Add/Edit Profile dialog.

External hardware only subchains

This section is visible when subchains are defined that only contain external hardware and no TAP group.

Auto

This column is only visible when Automatic Configuration is enabled. Subchains generated automatically by the system will have a tick. Being automatically generated means these subchains will track any future project changes to the JTAG chains.

Name

The name of the subchain used when configuring profiles and reset sequences.

External Hardware

Any external hardware included in the subchain.

Available Reset Sequences

This lists all Subchain Reset Sequences associated with the subchain. The built-in sequence is always included as an option, which for an external hardware only subchain is an empty sequence. When there is more than one reset sequence associated with a subchain, the sequence to use is determined per profile in the Add/Edit Profile dialog.

Subchains for both sections can be created, edited and removed using the buttons at the bottom of the subchains section.

Double-clicking in any subchain row anywhere except the TCK frequency column will open the Add/Edit Subchain dialog.

The Auto column is not visible when Automatic Configuration is disabled. Additionally the Target TCK frequency column is not visible when running in Classic Scans mode. In this case the TCK frequency of the project is set in the General Settings panel.