CoreSight Access Tool (CSAT)
The CoreSight Access Tool (CSAT) provides a scriptable low level interface to a target’s CoreSight Debug Access Port (DAP), which gives access to on-chip debug and system buses. CSAT is useful to perform initial bring-up tests before a debugger connection to the target is available.
CSAT enables the configuration of third party IP connected to the DAP, for example custom instrumentation hardware, and can be used while a debugger is connected to an ARM processor. This enables the debug of complex hardware-related problems.
Python Scripting
ARM target connection products implement powerful low level target control via Python scripts. For example, this allows users to configure them to automatically refresh the watchdog timer while they are connected to the target, and work-around hardware bugs.
RDDI and GDB-Wire Interfaces
RDDI is the main interface between ARM debuggers and target connection products. Third party debuggers, both for ARM and other processor cores, can connect to DSTREAM or RVI using an RDDI interface. The firmware in these hardware units has a flexible architecture to connect to multiple ARM and third party IP cores on an SoC via a single debug interface.
RDDI is freely available for download.
A low-level RDDI connection to RVI or DSTREAM can be used to gain access to the JTAG scan-chains inside the target device. This enables the unit to be used for simple tasks such as production testing.
The GDB-Wire interface to ARM target connection products enables the connection of GNU Debugger (GDB) to a target via JTAG or Serial-Wire Debug. This connection extends the functionality of GDB to include stop-mode debug: start, stop and change the state of processor and coprocessor registers, memory and peripherals.

