Arria® V SX and ST SoC Errata

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ID 683370
Date 7/14/2015
Public
Document Table of Contents
Document Table of Contents x
1. Arria® V SX and ST SoC Errata
1. Arria® V SX and ST SoC Errata x
1.1. Altera-Specific SoC Errata for Arria® V SX and ST Devices 1.2. Arm* Cortex* -A9 MPCore* and L2 Cache Errata 1.3. Revision History for Arria® V SX and ST SoC Errata
1.1. Altera-Specific SoC Errata for Arria® V SX and ST Devices x
1.1.1. Hard Processor System (HPS) 1.1.2. FPGA
1.1.1. Hard Processor System (HPS) x
1.1.1.1. EMAC RMII PHY Interface is Only Supported Through the FPGA Fabric 1.1.1.2. Hard Processor System Level 2 Cache Error Correction Code 1.1.1.3. Hard Processor System PLL Lock Issue After Power-on Reset or Cold Reset 1.1.1.4. HPS TAP Controller Is Reset By Cold Reset 1.1.1.5. SPI Slave Output Signals Cannot Be Isolated When Routed to the HPS Pins
1.1.2. FPGA x
1.1.2.1. False Configuration Failure in Active Serial Multi-Device Configurations
1.2. Arm* Cortex* -A9 MPCore* and L2 Cache Errata x
1.2.1. Arm* Cortex* -A9 MPU 1.2.2. Arm* L2 Cache Controller 1.2.3. Arm* CoreSight PTM
1.2.1. Arm* Cortex* -A9 MPU x
1.2.1.1. 761319: Ordering of Read Accesses to the Same Memory Location Might Be Uncertain 1.2.1.2. 775420: Particular Data Cache Maintenance Operation Which Aborts Might Lead to Deadlock 1.2.1.3. 782772: Speculative Execution of LDREX or STREX Instruction After a Write to Strongly Ordered Memory Might Lead to Deadlock 1.2.1.4. 761320: Full Cache Line Writes to the Same Memory Region From Both Processors Might Cause Deadlock 1.2.1.5. 845369: Under Very Rare Timing Circumstances Transition into Streaming Mode Might Create Data Corruption Description Impact Workaround Category 1.2.1.6. 740657: Global Timer Can Send Two Interrupts for the Same Event 1.2.1.7. 751476: Missed Watchpoint on the Second Part of an Unaligned Access Crossing a Page Boundary 1.2.1.8. 754322: Faulty MMU Translations Following ASID Switch 1.2.1.9. 764369: Data or Unified Cache Line Maintenance by MVA Fails on Inner-Shareable Memory 1.2.1.10. 782773: Updating a Translation Entry to Move a Page Mapping Might Erroneously Cause an Unexpected Translation Fault 1.2.1.11. 794072: A Short Loop Including DMB Instruction Might Cause a Denial of Service When the Other Processor Executes a CP15 Broadcast Operation 1.2.1.12. 794073: Speculative Instruction Fetches with MMU Disabled Might Not Comply with Architectural Requirements 1.2.1.13. 794074: A Write Request to an Uncacheable, Shareable Normal Memory Region Might be Executed Twice, Possibly Causing a Software Synchronization Issue 1.2.1.14. 725631: ISB is Counted in Performance Monitor Events 0x0C and 0x0D 1.2.1.15. 729817: MainID Register Alias Addresses Are Not Mapped on Debug APB Interface 1.2.1.16. 729818: In Debug State, the Next Instruction is Stalled When the SDABORT Flag is Set Instead of Being Discarded 1.2.1.17. 751471: DBGPCSR Format Is Incorrect 1.2.1.18. 752519: An Imprecise Abort Might Be Reported Twice on Non-Cacheable Reads 1.2.1.19. 754323: Repeated Store in the Same Cache Line Might Delay the Visibility of the Store 1.2.1.20. 756421: Sticky Pipeline Advance Bit Cannot be Cleared from Debug APB Accesses 1.2.1.21. 757119: Some Unallocated Memory Hint Instructions Generate an UNDEFINED Exception Instead of Being Treated as a NOP 1.2.1.22. 761321: MRC and MCR Are Not Counted in Event 0x68 1.2.1.23. 764319: Read Accesses to DBGPRSR and DBGPRCR May Generate an Unexpected UNDEF 1.2.1.24. 771221: PLD Instructions Might Allocate Data in the Data Cache Regardless of the Cache Enable Bit Value 1.2.1.25. 771224: Visibility of Debug Enable Access Rights to Enable/Disable Tracking is Not Ensured by an ISB 1.2.1.26. 771225: Speculative Cacheable Reads to Aborting Memory Regions Clear the Internal Exclusive Monitor and May Lead to Livelock 1.2.1.27. 775419: PMU Event 0x0A Might Count Twice the LDM PC ^ Instruction with Base Address Register Write-Back 1.2.1.28. 782774: A Spurious Event 0x63 Can be Reported on an LDREX That is preceded by a Write to Strongly Ordered Memory Region
1.2.2. Arm* L2 Cache Controller x
1.2.2.1. 754670: A Continuous Write Flow Can Stall a Read Targeting the Same Memory Area 1.2.2.2. 765569: Prefetcher Can Cross 4 KB Boundary if Offset is Programmed with Value 23 1.2.2.3. 729815: The High Priority for SO and Dev Reads Feature Can Cause Quality of Service Issues to Cacheable Read Transactions
1.2.3. Arm* CoreSight PTM x
1.2.3.1. 720107: Periodic Synchronization Can Be Delayed and Cause Overflow 1.2.3.2. 711668: Configuration Extension Register Has Wrong Value Status
1. Arria® V SX and ST SoC Errata

1.2.1.5. 845369: Under Very Rare Timing Circumstances Transition into Streaming Mode Might Create Data Corruption

Description

Under very rare timing circumstances, data corruption might occur on a dirty cache line that is evicted from the L1 data cache due to another cache line being entirely written.

The erratum requires the following conditions:

  • The CPU contains a dirty line in its data cache.
  • The CPU performs at least four full cache line writes, one of which is causing the eviction of the dirty line.
  • The other CPU, or the ACP, is performing a read or write operation on the dirty line.

The issue requires very rare timing conditions to reach the point of failure. These timing conditions depend on the CPU micro-architecture, and are not controllable in software:

  • The CPU must be in a transitional mode that might be triggered by the detection of the first two full cache line writes.
  • The evicted line must remain stalled in the eviction buffer, which is likely to be caused by congested write traffic.
  • The other coherent agent, either the other CPU or the ACP, must perform its coherency request on the evicted line while it is in the eviction buffer.

Impact

This erratum might lead to data corruption.

Workaround

A workaround for this erratum is provided by setting bit[22] of the undocumented Diagnostic Control Register to 1. This register is encoded as CP15 c15 0 c0 1. The bit can be written in secure state only, with the following read-modify-write code sequence: 

MRC p15,0,rt,c15,c0,1 
ORR rt,rt,#0x00400000
MCR p15,0,rt,c15,c0,1

When this bit is set, the processor is unable to switch into read-allocate (streaming) mode, which means this erratum cannot occur.

Setting this bit could possibly result in a visible drop in performance for routines that perform intensive memory accesses, such as memset() or memcpy(). However, the workaround is not expected to create any significant performance degradation in most standard applications.

Category

Category 2

Level Two Title