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 (Xilinx Answer 47916) - Zynq-7000 SoC Silicon Revision Differences. |
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.
| Answer Number | Answer Title | Version Found | Version Resolved |
|---|---|---|---|
| 47916 | Zynq-7000 SoC Devices - Silicon Revision Differences | N/A | N/A |
| AR# 47559 | |
|---|---|
| Date | 05/23/2018 |
| Status | Active |
| Type | Design Advisory |
| Devices | |