Version 3.9 of XJDeveloper introduces the ability to control which External Hardware machines operate in each Subchain, and integrates this control into the Dynamic Chains feature. This means that any test may now be configured to use just JTAG, just External Hardware, or a combination of both, to drive signals on the circuit under test.
This allows you to run JTAG tests before External Hardware is connected, or conversely run tests before the JTAG chain is operational, by driving the circuit using External Hardware. An example, an XJEase test could use I2C to communicate with an on-board power supply in order to enable power for the rest of the circuit. Once the power rails are up, testing can continue using the JTAG devices on the board too.
To customise your tests, this is configurable per-Subchain in the Subchains dialog of XJDeveloper, accessible from the Configure Profiles dialog on the JTAG Chain screen. See the installed help files for more details of how to use this feature.