3.4 Trace Data Analysis

Notes on acquisition of graph data through Trace data analysis are listed below.

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It is not possible to display changes in values in the following case:

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In sections where variables have been assigned to registers via compiler optimization
(because reads/writes of variables in such sections cannot be acquired as trace data.)

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When a 2-byte region is written in units of 1 byte, or a 4-byte region is written in units of 1 or 2 bytes

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When the debug tool or OCD internal trace cannot acquire trace data of the access type (read/write)
(because the graph is rendered by analyzing trace data of the access type.)

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If you mix a Point Trace event and a Trace event specified sections, then the instruction line at the end of the Trace event specified section may be applied to subsequent Point Trace event. For this reason, although [Location] in the pop-up display on the graph should be "-", an invalid file name and line number may appear.

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bit-type, Boolean-type, and _Bool-type variables and structure bit-fields are analyzed in byte units.
In cases where bit-type, Boolean-type, and _Bool-type variables and structure bit-fields are allocated to the same address, even a point where access to a single variable or structure bit-field occurs is recorded as a transition point in the graph.
Double-clicking on the transition point will jump to the source line of another variable that is allocated to the same address.
If a structure bit-field is assigned to several bytes, some of the information on the byte access is not included in the output trace data. This portion is displayed as a lost section (see "(a) Graph") in the graph since the value of the variable cannot be analyzed.


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[E20[RX]]

If [Stop Trace]/[Start Trace] of the context menu on the Trace panel is selected during a program execution, an invalid chart may be displayed.

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[E20[RX]]

In the debug tool's Property panel, when the [Trace data type] property in the [Trace] category on the [Debug Tool Settings] tab is set to [Branch], the acquisition time of trace data will increase because complement of instructions between branch instructions is performed.
If you wish to display graphs focusing only on variables, we recommend selecting [Data access] in this property.