You copied the Doc URL to your clipboard.

ERR<n>MISC3, Error Record Miscellaneous Register 3, n = 0 - 65534

The ERR<n>MISC3 characteristics are:


IMPLEMENTATION DEFINED error syndrome register. The miscellaneous syndrome registers might contain:

  • Information to locate where the error was detected.
  • If the error was detected within a FRU, the identity of the FRU.
  • A Corrected error counter or counters.
  • Other state information not present in the corresponding status and address registers.

If the node that owns error record n supports the RAS Timestamp Extension (ERR<q>FR.TS != 0b00), then ERR<n>MISC3 contains the timestamp value for error record n when the error was detected. Otherwise the contents of ERR<n>MISC3 are IMPLEMENTATION DEFINED.


This register is present only when (an implementation implements ERR<n>MISC3 or RAS System Architecture v1.1 is implemented) and error record <n> is implemented. Otherwise, direct accesses to ERR<n>MISC3 are RES0.

ERR<q>FR describes the features implemented by the node that owns error record <n>. <q> is the index of the first error record owned by the same node as error record <n>. If the node owns a single record, then q = n.

For IMPLEMENTATION DEFINED fields in ERR<n>MISC3, writing zero returns the error record to an initial quiescent state.

In particular, if any IMPLEMENTATION DEFINED syndrome fields might generate a Fault Handling or Error Recovery Interrupt request, writing zero is sufficient to deactivate the Interrupt request.

Fields that are read-only, non-zero, and ignore writes are compliant with this requirement.

If RAS System Architecture v1.1 is not implemented, Arm recommendeds that ERR<n>MISC3 does not require zeroing to return the record to a quiescent state.


Arm recommends that any IMPLEMENTATION DEFINED syndrome field that can generate a Fault Handling, Error Recovery, Critical, or IMPLEMENTATION DEFINED, interrupt request is disabled at Cold reset and is enabled by software writing an IMPLEMENTATION DEFINED nonzero value to an IMPLEMENTATION DEFINED field in ERR<q>CTLR.


ERR<n>MISC3 is a 64-bit register.

Field descriptions

The ERR<n>MISC3 bit assignments are:

When ERR<q>FR.TS != 0b00:

TS, bits [63:0]

Timestamp. Timestamp value recorded when the error was detected. Valid only if ERR<n>STATUS.V == 0b1.

On a Cold reset, this field resets to an architecturally UNKNOWN value.

Access to this field is RO or RW.

When ERR<q>FR.TS == 0b00:



Accessing the ERR<n>MISC3

Reads from ERR<n>MISC3 return an IMPLEMENTATION DEFINED value and writes have IMPLEMENTATION DEFINED behavior.

If the Common Fault Injection Mechanism is implemented by the node that owns this error record, and ERR<q>PFGF.MV is 0b1, then some parts of this register are read/write when ERR<n>STATUS.MV == 0b1. See ERR<n>PFGF.MV for more information.

For other parts of this register, or if the Common Fault Injection Mechanism is not implemented, then Arm recommends that:

  • Miscellaneous syndrome for multiple errors, such as a corrected error counter, is read/write.
  • When ERR<n>STATUS.MV == 0b1, the miscellaneous syndrome specific to the most recently recorded error ignores writes.

These recommendations allow a counter to be reset in the presence of a persistent error, while preventing specific information, such as that identifying a FRU, from being lost if an error is detected while the previous error is being logged.

ERR<n>MISC3 can be accessed through the memory-mapped interfaces:

RAS0x038 + (64 * n)ERR<n>MISC3

Accesses on this interface are RW.