6.4.2. Normal Data packets

The Normal Data packet header is used for:

A Normal Data packet comprises the following contiguous components:

Normal Data packet header

Output first. Always present.

Data address

Present if both of the following conditions are satisfied:

  • data address tracing is enabled in the ETMCR

  • the A bit in the header is set to 1.

Data addresses consist of one to five bytes. To enable the decompressor to detect the last byte, bit [7] of each byte is set to 1 if there are more address bytes to follow. Bit [7] is LOW in the last address byte. Whether or not data addresses are traced must be statically determined before tracing begins.

Data value

Present only if data value tracing is enabled in the ETMCR.

Normal Data packets correspond to the most recently-traced data instruction. This is to support processors where instructions that do not perform a data transfer might execute before a previous transfer completes.

64-bit data transfers

When data for LSM instructions is output, the data address is output with the first data packet only.

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