How to Configure the ITM

The following example describes how to output trace data in asynchronous trace mode.

Configure the TPIU for asynchronous trace mode. Refer to How to Configure the TPIU.

1. 1.Enable the write accesses into the ITM registers by writing “0xC5ACCE55” into the Lock Access Register (Address: 0xE0000FB0)
2. 2.Write 0x00010015 into the Trace Control register:
   • Enable ITM.
   • Enable Synchronization packets.
   • Enable SWO behavior.
   • Fix the ATB ID to 1.
3. 3.Write 0x1 into the Trace Enable register:
   • Enable the Stimulus port 0.
4. 4.Write 0x1 into the Trace Privilege register:
   • Stimulus port 0 only accessed in privileged mode (Clearing a bit in this register will result in the corresponding stimulus port being accessible in user mode.)
5. 5.Write into the Stimulus port 0 register: TPIU (Trace Port Interface Unit)

   The TPIU acts as a bridge between the on-chip trace data and the Instruction Trace Macrocell (ITM).

   The TPIU formats and transmits trace data off-chip at frequencies asynchronous to the core.