9.11.2. Write access

When trace capture is disabled (TraceCaptEn=0), the RAM Write Pointer Register is used to generate the RAM address for writing data from the RAM Read Data Register. Compare this with trace capture is enabled, and trace data storage from the ATB interface. The data to be stored in the RAM Write Data Register is derived from an APB write transfer to the APB interface.

Updating the RAM Read Data Register automatically triggers a RAM access to write the register contents into the Trace RAM at the address present in the RAM Write Pointer Register. On completion of the write cycle the RAM Write Pointer Register is automatically incremented.

Note

A write access to the RAM Write Pointer Register does not initiate a write transfer to the Trace RAM, only a write to the RAM Read Data Register causes a RAM write.

The RAM Write Pointer Register must be programmed before trace capture is re-enabled.

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