Visible to Intel only — GUID: ebl1685725018729
Ixiasoft
Visible to Intel only — GUID: ebl1685725018729
Ixiasoft
3.1.5. 1030596: Cycle count value in timestamp packet might be incorrect
Description
When a timestamp packet is generated in the trace, the timestamp packet can indicate the cycle count between the previous cycle count element and the element the timestamp is associated with. This can be used to infer the alignment between cycle count elements and the global timestamp. Timestamp packets can be inserted in the trace stream some time after the element the timestamp is associated with gets traced. Because of this erratum, the cycle count indicated in the timestamp packet will be determined by the time when the packet is inserted in the trace stream.
Conditions
- Timestamping must be enabled, with TRCCONFIGR.TS== 1.
- Cycle counting must be enabled, with TRCCONFIGR.CCI== 1.
Impact
The cycle count for the timestamp packet will indicate a time after the element which was used to capture the timestamp. If there has been a gap in the tracing of elements which can be timestamped, this error can be large. This does not affect the incremental cycle count values which are related to instructions being committed.
Workaround
There is no workaround for this erratum.
Category
Category C