Fujitsu Fujitsu SPARC64 V Format of Error-Marking Data, Table P-4Format of Error-Marked Data

Models: Fujitsu SPARC64 V

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When a hardware unit first detects an uncorrected error in the cacheable data, the hardware unit replaces the data and ECC of the cacheable data with a special pattern that identifies the original error source and signifies that the data is already marked.

The error marking helps identify the error source and prevent multiple error reports by a single error even after several cache lines transfer with uncorrected data.

The following data are protected by the single-bit error correction and double-bit error detection ECC code attached to every doubleword:

Main memory (DIMM)

UPA packet data containing cache line data and interrupt packet data

U2 (unified level 2) cache data

D1 cache data

The cacheable area block held by the channel

The ECC applied to these data is the ECC specified for UPA.

When the CPU and channel (U2P) detect an uncorrected error in the above cacheable data that is not yet marked, the CPU and channel execute error marking for the data block with an UE.

Whether the data with UE is marked or not is determined by the syndrome of the doubleword data, as shown in TABLE P-2.

TABLE P-3Syndrome for Data Marked for Error

Syndrome

Error Marking Status

Type of Uncorrected Error

 

 

 

7F16

Marked

Marked UE

Multibit error pattern except for 7F16

Not marked yet

Raw UE

The syndrome 7F16 indicates a 3-bit error in the specified location in the doubleword. The error marking replaces the original data and ECC to the data and ECC, as described in the following section. The probability of syndrome 7F16 occurrence other than the error marking is considered to be zero.

The Format of Error-Marking Data

When the raw UE is detected in the cacheable data doubleword, the erroneous doubleword and its ECC are replaced in the data by error marking, as listed in TABLE P-4.

TABLE P-4Format of Error-Marked Data

Data/ECC

Bit

Value

 

 

 

data

63

Error bit. The value is unpredictable.

 

62:56

0 (7 bits).

 

55:42

ERROR_MARK_ID (14 bits).

 

 

 

158 SPARC JPS1 Implementation Supplement: Fujitsu SPARC64 V • Release 1.0, 1 July 2002

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Fujitsu Fujitsu SPARC64 V manual Format of Error-Marking Data, Table P-3Syndrome for Data Marked for Error