10.2.6. Start/stop block

The start/stop block provides a single-bit resource that can be used as an input to other parts of the resource logic, including the trace enable logic. The start/stop block can only be controlled by using the EmbeddedICE inputs to the ETM. The DWT controls these inputs.

The start/stop block is set to the start state if any of the EmbeddedICE watchpoint inputs selected as start resources in ETMTESSEICR go HIGH. The start/stop block is set to the stop state if any of the EmbeddedICE watchpoint inputs selected as stop resources in ETMTESSEICR go LOW.

If bit [25] of ETMTECR1 is 1, tracing will only be enabled when the start/stop block is in the start state.

Tracing is also only enabled when the result of evaluating the Trace Enable Event is TRUE. This event can be set to always be TRUE by programming a value of 0x6F to ETMTEEVR. For more information see the Embedded Trace Macrocell Architecture Specification.

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