Halted System Debug (HSD) means that you can only debug a target when it is not running. This means that you must stop your debug target before carrying out any analysis of your system.

HSD mode is not suitable for real-time systems where stopping the debug target might damage your hardware, for example disk controllers.

Running System Debug (RSD) means that you can debug a target when it is running. This means that you do not have to stop your debug target before carrying out any analysis of your system. RSD gives access to the application using a Debug Agent (DA) that resides on the target and is typically considered to be part of the OS. The Debug Agent is scheduled along with other tasks in the system.

RSD is only available where supported by your debug target. It relies on having RealView Debugger OS extensions installed and is not provided as part of the base product.

RSD mode is intrusive because it uses resources on your debug target and makes demands on the application you are debugging. However, this debugging mode provides extra functionality not available when using HSD, for example, RSD enables you to debug threads individually or in groups, where supported by your OS and Debug Agent.