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winIDEA Help

Version: 9.21.111

DWT Data Comparator on Cortex-M

Each comparator can be configured for a specific address or/and for an address range (Address comparators). All comparators have a LSB masking register which implements an ignore mask. The size of the ignore mask is 0-31 bits, applied to address range matching. The range can be specified via Ignore LSB bits drop-down menu.

Comparator 0 can compare against the clock cycle counter (CYCCNT).

Comparator 1 supports data comparison (Data comparator) and linking with another comparator. It can be set to two addresses or/and two ranges, and data value. In this case Comparator 3 and/or 2 are reserved.

 

A full DWT module contains four comparators that you can configure as:

  • a hardware watchpoint
  • an ETM trigger
  • a PC sampler event trigger
  • a data address sampler event trigger.

 

Note that a more simple configuration is possible via Analyzer Configuration / Profiler page dialog and Profiler Data Area dialog. Follow online tutorial Tracing with iSYSTEM tools which will guide you through basic configurations.

 

Configure via Profiler Data Area dialog

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  1. Open View / Analyzer / Analyzer Configuration button.
  2. Check Profiler in the Analyzer Configuration / Hardware page.
  3. Check Data in the Analyzer Configuration / Profiler page.
  4. Click New / Trace in Data Areas section.

 

Refer to Data Profiling chapter for more information.

 

 

Manual configuration of ARM Cortex-M Comparator 1

For specific use cases and linking the Comparator 1 winIDEA offers manual configuration of the DWT module.

 

Use cases cover comparing values on Address or/and Data with an option Ignore LSB bits:

1. Address

 

2. Address and Data

 

3. Address 1 / Address 2 and Data

 

 

Open the Trigger dialog

Open View / Analyzer and click the Analyzer Configuration button AnalyzerConButton.

 

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  1. Enable Manual Trigger/Recorder configuration.
  2. Make sure Processes, the application you wish to record (e.g. App/ CORE0) and Profiler are enabled.
  3. Press Configure.

 

 

Enable and the DWT module and configure Comparator 0

To link Comparator 1 with Comparator 3 and/or Comparator 2, Comparator 0 has to be configured first.

 

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Enable the DWT component and configure Comparator 0

  1. Open the DWT CORE0 page.
  2. Enable Comparator 0.
  3. Select Write Access from the drop-down menu.
  4. Select an address in the Address field. e.g. iDataTrace.
  5. Select sample data value from the Action drop-down menu.

 

 

Use case: Compare on Address

Compare on Address on Data Access

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Configure Comparator 1

  1. Enable Comparator 1.
  2. Select Write Access from the drop-down menu.
  3. Enable Address 1 and select and address in the field.
  4. Select sample data value from the Action drop-down menu.

 

 

Compare on Address Range on Data Access

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Configure Comparator 1 with option Ignore LSB bits

  1. Enable Comparator 1.
  2. Select Write Access from the drop-down menu.
  3. Enable Address 1 and select and address in the field.
  4. Select sample data value from the Action drop-down menu.
  5. Select a number from the Ignore LSB bits drop-down menu.

 

 

Use case: Compare on Address and Data

Compare on Address and Data Value on Data Access

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Configure Comparator 1

  1. Enable Comparator 1.
  2. Select Write Access from the drop-down menu.
  3. Enable Address 1 and select and address in the field.
  4. Enable Data and select the HEX value.
  5. Select data size from the Data Size drop-down menu.

 

Comparator 3 is reserved.

 

 

Compare on Address Range and Data Value on Data Access

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Configure Comparator 1 with option Ignore LSB bits

  1. Enable Comparator 1.
  2. Select Write Access from the drop-down menu.
  3. Enable Address 1 and select and address in the field.
  4. Enable Data and select the HEX value.
  5. Select data size from the Data Size drop-down menu.
  6. Select a number from the Ignore LSB bits drop-down menu.

 

Comparator 3 is reserved.

 

 

Use case: Compare on Address 1 / Address 2 and Data

Compare on Address 1 or Address 2 and Data Value

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Configure Comparator 1

  1. Enable Comparator 1.
  2. Select Write Address from the drop-down menu.
  3. Enable Address 1 and select and address in the field.
  4. Enable Data and select the HEX value.
  5. Select data size from the Data Size drop-down menu.
  6. Enable Address 2 and select and address in the field.

 

Comparator 2 and 3 are reserved.

 

 

Compare on Address 1 range or Address 2 range and Data value

Cortex-DWT-Adress1-2

Configure Comparator 1 with Ignore LSB bits

  1. Enable Comparator 1.
  2. Select Write Address from the drop-down menu.
  3. Enable Address 1 and select and an address in the field.
  4. Select a number from the Ignore LSB bits drop-down menu for Address 1.
  5. Enable Data and select the HEX value.
  6. Select data size from the Data Size drop-down menu.
  7. Enable Address 2 and select and an address in the field.
  8. Select a number from the Ignore LSB bits drop-down menu for Address 2.

 

Comparator 2 and 3 are reserved.

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