4.1. About trace information

The trace port outputs two different types of trace information:


Instruction trace shows the flow of execution of the processor. It provides a list of all the instructions that were executed, giving the address of each instruction, indicating which instructions failed their condition codes and which instructions were subject to an exception. This information is highly compressed. Instruction trace is described in Instruction trace.


Data trace shows the data accesses performed by the processor that occur as a result of the processor executing a load or store operation. For data accesses it is possible to output both the address and the data value. However, you can choose to compress the data trace by only outputting either the address or the data value. Additional compression is performed by later protocols. Data trace is described in Data trace.


In this specification, a packet is a discrete quantity of trace information comprising one or more bytes. In previous versions of this document, the word packet and byte were used interchangeably.

Copyright © 1999-2002, 2004-2009, 2011 ARM Limited. All rights reserved.ARM IHI 0014Q