Cyclone® V SX, ST and SE SoC Device Errata

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ID 683618
Date 9/25/2015
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Document Table of Contents x
1. Cyclone® V SX, ST and SE SoC Device Errata
1. Cyclone® V SX, ST and SE SoC Device Errata x
1.1. Intel® -Specific SoC Errata for Cyclone® V SX, ST, and SE SoC Devices 1.2. Arm* Cortex* -A9 MPCore* and L2 Cache Errata 1.3. Revision History for Cyclone® V SX, ST, and SE SoC Device Errata
1.1. Intel® -Specific SoC Errata for Cyclone® V SX, ST, and SE SoC 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. External Memory Interface (EMIF) Maximum Frequency Specification Updage 1.1.2.2. Fractional PLL Phase Alignment Error 1.1.2.3. Power Connection Recommendation for Cyclone® V SoC ES Devices 1.1.2.4. Configuration via Protocol (CvP) 1.1.2.5. Usermode High Icc 1.1.2.6. False Configuration Failure in Active Serial Multi-Device Configuration x1 Mode 1.1.2.7. JTAG Programming Operation Issue
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 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 Description Impact Workaround Category 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. Cyclone® V SX, ST and SE SoC Device Errata

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

Description

A processor that continuously executes a short loop containing a DMB instruction might prevent a CP15 operation broadcast by the other processor making further progress, causing a denial of service.

This erratum only affects dual Cortex* -A9 MPCore* devices.

This erratum requires the following conditions:

  • A dual core device with the processors working in SMP mode (ACTLR.SMP=1).
  • One of the processors continuously executes a short loop containing at least one DMB instruction.
  • The other processor executes a CP15 maintenance operation that is broadcast, meaning that this processor has enabled the broadcasting of CP15 operations (ACTLR.FW=1).

For this erratum to occur, the short loop containing the DMB instruction must meet both of the following additional conditions:

  • No more than 10 instructions other than the DMB are executed between each DMB.
  • No non-conditional Load or Store, or conditional Load or Store that pass the condition code check, are executed between each DMB.

When all the conditions for this erratum are met, the short loop creates a continuous stream of DMB instructions that may cause a denial of service by preventing the processor executing the short loop from executing the received broadcast CP15 operation. As a result, the processor that originally executed the broadcast CP15 operation is stalled until the execution of the loop is interrupted.

Note that because the process issuing the CP15 broadcast operation cannot complete operation, it cannot enter any debug mode and cannot take any interrupt. If the processor executing the short loop also cannot be interrupted, for example if it has disabled its interrupts, or if no interrupts are routed to this processor, this erratum might cause a system livelock.

Impact

This erratum might create performance issues, or in the worst case it might cause a system livelock if the processor executing the DMB is in an infinite loop that cannot be interrupted.

Workaround

This erratum can be worked around by setting bit[4] of the undocumented Diagnostic Control Register to 1. This register is encoded as CP15 c15 0 c0 1.

This bit can be written in the secure state only, with the following read-modify-write code sequence: 

MRC p15,0,rt,c15,c0,1
ORR rt,rt,#0x10
MCR p15,0,rt,c15,c0,1

When it is set, this bit causes the DMB instruction to be decoded and executed like a DSB. Using this software workaround is not expected to have any impact on the overall performance of the processor on a typical code base.

Other workarounds are also available for this erratum, to either prevent or interrupt the continuous stream of DMB instructions that causes the deadlock. Examples include:

  • Inserting a non-conditional Load or Store instruction in the loop between each DMB.
  • Inserting additional instructions in the loop, such as NOPs, to avoid the processor seeing back to back DMB instructions.
  • Making the processor that is executing the short loop take regular interrupts.

Category

Category 3

Level Two Title