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AR# 47559 Zynq-7000, APU - MRC and MCR Instructions are not Counted in Event 0x68

The MRC and MCR instructions are not counted in the total number of instructions passing through the Register rename pipeline stage. The values of event 0x68 and PMUEVENT[9:8] are imprecise.

Impact:

Minor. The count of event 0x68 and PMUEVENT[9:8] are imprecise, omitting the number of MCR and MRC instructions. The inaccuracy of the total count depends on the rate of MRC and MCR instructions in the code.

Work-around:

No work-around is possible to achieve the functionality of counting how many instructions are precisely passing through the register rename pipeline stage when the code contains some MRC or MCR instructions.

Configurations Affected:

Systems that use one or both ARM processors.

Device Revision(s) Affected: All, no plan to fix. Refer to Zynq-7000 Device Advisory Master Answer Record

No work-around is possible to achieve the functionality of counting how many instructions are precisely passing through the register rename pipeline stage when the code contains some MRC or MCR instructions.

AR# 47559
Date Created 05/30/2012
Last Updated 08/06/2012
Status Active
Type Design Advisory
Devices
  • Zynq-7000
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