
ERR003721
Chip Errata for the i.MX 6Dual/6Quad and i.MX 6DualPlus/6QuadPlus, Rev. 6.1, 06/2016
24
NXP Semiconductors
Description:
Under very rare timing circumstances, the automatic Data prefetcher might cause address hazard
issues, possibly leading to a data corruption or a deadlock of the processor.
Conditions:
The erratum can only happen when the Data Cache and MMU are enabled in the following cases:
• On all memory regions marked as Write-Back Non-Shared, when the Data Prefetcher in L1 is
enabled (ACTLR[2]=1’b1), regardless of the ACTLR.SMP bit.
• On all memory regions marked as Write-Back Shared, when the Data Prefetch Hint in L2 is
enabled (ACTLR[1]=1’b1), and when the processor is in SMP mode (ACTLR.SMP=1’b1).
Projected Impact:
When the bug happens, a data corruption or a processor deadlock can happen.
Workarounds:
The workaround for this erratum requires not enabling the automatic Data Prefetcher by keeping
ACTRL[2:1]=2’b00, which is the default value on exit from reset.
Although this feature might show significant performance gain on a few synthetic benchmarks, it
usually has no impact on real systems. It means, this workaround is not expected to cause any
visible impact on final products.
Proposed Solution:
No fix scheduled
Linux BSP Status:
Software workaround not needed in the BSP. Functionality or mode of operation in which the
erratum may manifest itself is not used. Linux BSP keeps ACTRL[2:1]=2’b00.
ERR003721
ARM: 751473—Under very rare circumstances, Automatic Data
prefetcher can lead to deadlock or data corruption