The ETM is an optional debug component that enables reconstruction of program execution. The ETM is designed to be a high-speed, low-power debug tool that only supports instruction trace. This ensures that area is minimized, and that gate count is reduced.

The ETM implements ARM ETM architecture v3.5. See the ARM Embedded Trace Macrocell Architecture Specification.

The ETM traces all 32-bit Thumb instructions as a single instruction. The ETM traces instructions following an IT instruction as normal conditional instructions. The decompressor does not need to refer to the IT instruction.

You can use the CoreSight ETM-M3 either with the Cortex-M3 Trace Port Interface Unit (M3-TPIU), or as part of a CoreSight system.