10.2.3. Data and instruction address compare resources

The DWT provides four address comparators on the data bus that provide debug functionality. Within the DWT unit, you can specify the functions triggered by a match, and one of these functions is to generate an ETM match input. These inputs are presented to the ETM as Embedded In Circuit Emulator (ICE) comparator inputs.

A single DWT resource can trigger an ETM event and also generate instrumentation trace directly from the same event.

You can configure the four DWT comparators individually to compare with the address of the current executing instruction to permit the ETM access to an instruction address compare resource. These inputs are presented to the ETM as Embedded ICE comparator inputs. The DWT provides either 1 or 4 comparators, depending on the implementation of the processor.


Using a DWT comparator as an instruction address comparator reduces the number of available data address comparisons.

See Chapter 8 Data Watchpoint and Trace Unit for more information about the DWT unit.

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