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IAR Embedded Workbench for Arm 9.70.x

Trace Start breakpoints dialog box (I-jet and CMSIS-DAP)

In this section:

The Trace Start dialog box is available from the context menu that appears when you right-click in the Breakpoints window. You can also right-click in the editor window or the Disassembly window, and then choose Toggle Breakpoint (Trace Start).

TraceStartBrpDlg_Ijet_1_ARM.PNG

Use this dialog box to set the conditions that determine when to start collecting trace data. When the trace condition is triggered, the trace data collection is started.

Requirements

One of these alternatives:

  • The C-SPY I-jet driver

  • The C-SPY CMSIS-DAP driver

  • A device with data matching capabilities.

Trigger at

Specify the starting point of the code section for which you want to collect trace data. You can specify a variable name, an address, or a cycle counter value.

Access Type

Selects the type of memory access that triggers the breakpoint:

Read/Write

Reads from or writes to location.

Read

Reads from location.

Write

Writes to location.

Fetch

Accesses at execution address.

Any accesses of the specified type will activate the trace data collection.

Match data

Enables matching of the accessed data. Choose between:

Value

Specify a data value.

Mask

Specify which part of the value to match (word, halfword, or byte).

Use the Match data options in combination with the Read/Write, Read, or Write access types for data. This option can be useful when you want a trigger when a variable has a certain value.

Note

The Match data options are only available when using a Cortex-M device. For Cortex-M devices, only one breakpoint with Match data can be set. Such a breakpoint uses two breakpoint resources.

Size

Controls the size of the address range, that when reached, will trigger the start of the trace data collection. Choose between:

Auto

Sets the size automatically. This can be useful if Trigger at contains a variable.

Manual

Specify the size of the breakpoint range manually.

Trigger range

Shows the requested range and the effective range to be covered by the trace data collection. The range suggested is either within or exactly the area specified by the Trigger at and the Size options.

Extend to cover requested range

Extends the range so that a whole data structure is covered. For data structures that do not fit the size of the possible ranges supplied by the hardware breakpoint unit, for example three bytes, the range will not cover the whole data structure. Note that the range will be extended beyond the size of the data structure, which might cause false triggers at adjacent data.

This option is not enabled for Arm7/9 devices because the range for such devices will always cover the whole data structure.