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Debug Settings

The Debug dialog configures the way ULINKplus connects to the target hardware. When Pack support is enabled some device options or settings are controlled by the Software Pack and therefore grey or not available. As highlighted on the figure below there are 5 configurations groups in the dialog:

Options for Target - Debug - Use ULINKplus Selection

ULINKplus - JTAG/SW Adapter shows information about the debug unit.

Serial No:
Select the serial number of the ULINKplus adapter to use. This is useful when multiple adapters are connected to the PC. Any selects the first adapter in the list.
Firmware Version
Displays the firmware software revision of the selected ULINKplus.
Enable to generate sequences that switch between JTAG and Serial Wire (SW) mode. Disable this option for devices with only a SW or only a JTAG interface.
Selects the debug port type to use: JTAG or SW (Serial Wire).
Max Clock
Sets the maximum clock rate.

SW Device/JTAG Device Chain shows status information about the connection to the target devices.

Automatic Detection
ULINKplus detects the connected devices and displays the IDCODE and known device names.
Manual Configuration
Specify the parameters of each device in a JTAG device chain when chaining multiple targets.
Specify the identifier of the Access Port in multi-core devices with a single Debug Port (DP). The Access Port specification depends on the Arm Debug Interface (ADI) supported in the device.
  • For APv1 (ADIv5):
    • The AP value range is 0 to 255.
    • For single core devices, set AP to 0 (default).
    • For a multi-core device, core 0 is expected to have AP=0 and core 1 AP=1. However, the port identifiers are specified by the device manufacturer.
  • For APv2 (ADIv6):
    • Only SWD connection to ADIv6 target systems is currently supported.
    • The AP value range is 0x00000000 to 0xFFFFFFFF. The value needs to be set by a user for a target sub-system based on the information provided by the device vendor in documentation.
    • If AP value is set to 0xFFFFFFFF then µVision debugger will automatically connect to the AP of the first auto-detected CPU.
    • Debugger automatically requests power using Granular Power Requester (GPR) from Class 0x9 ROM Tables.
    • Only top-level APs are supported, not "nested APs" (AP exposing its registers via target memory accesses of a higher-level AP).

Connect & Reset Options controls device connection and reset behavior.

Control operations that execute at debugger start:
  • Normal stop the CPU after connect.
  • with Pre-reset apply a hardware reset before connect.
  • under Reset holds the hardware reset signal active during connect. Use this option when the user program disables the JTAG/SW interface by mistake.
  • without Stop connect without stopping the CPU. Useful to hot-plug to a running target.
Reset after Connect
When enabled, a reset is issued after the connect operation. Refer to Start Sequence for details.
Log Debug Accesses
When enabled, create a log file (ULINKplus_DebugLog_nnnn.log) in the project folder to analyze debugger communication issues. Disable this option for normal operation.
Control how the debugger performs a Reset Sequence to the device. The available options vary when Pack support is enabled.
  • HW RESET assert hardware reset (nReset) signal on the JTAG/SWD connector.
  • SYSRESETREQ set the SYSRESETREQ bit to perform a software reset (Cortex-M core and on-chip peripherals are reset).
  • VECTRESET performs a CPU reset (on-chip peripherals are not reset). VECTRESET is not supported on Cortex-M0, Cortex-M0+, Cortex-M1, and Armv8-M cores.
  • Custom select a custom reset method (available when defined in the Software Pack and Pack support is enabled).
  • Autodetect selects the best suitable reset method for a known device. For unknown devices SYSRESETREQ is used. (Not available when Pack support is enabled.)
Stop after Reset
Stop the CPU when executing the reset vector (this option enables the Cortex-M Reset Vector Catch).

Cache Options improve the debugger performance during debugging by caching target memory areas into the PC memory. Enable caching options to get maximum performance.

Cache Code
The debugger assumes that downloaded program code will never change. When enabled, the debugger never reads the program code from the target. Disable this option when the application includes self-modifying code or the program code might get overwritten.
Cache Memory
Determines whether memory displays are updated during a program stop. When enabled, the debugger does not update memory displays until the next program execution. Disable this option to display the actual memory content (for example, the content of memory mapped peripherals) when the debugger is halted.

Download Options control the program code updates at debugger start.

Verify Code Download
Compare the content of the target memory with the application program loaded in the debugger. Enable this option to prevent debugging of wrong code, for example when working with various project targets.
Download to Flash
By default, this option is disabled to avoid multiple code downloads to Flash memory defined under Flash Download. When enabled, download code to all memory regions including Flash memory. For more information, refer to the knowledgebase article µVision Debugger: Error 57: Illegal Address in Debugger Output Window.
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