DERRSYN-DRAM Error Syndrome Register Device

3.5.19DERRSYN—DRAM Error Syndrome Register (Device 0)

This register is used to report the ECC syndromes for each quadword of a 32 byte-aligned data quantity read from the system memory array.

Bit	Description

7:0	DRAM ECC Syndrome (DECCSYN). After a system memory ECC error, hardware loads this
	field with a syndrome that describes the set of bits found to be in error.
	Note: This field is locked from the time that it is loaded up to the time when the error flag is
	cleared by software. If the first error was a single bit, correctable error, then a subsequent
	multiple bit error will overwrite this field. In all other cases, an error that occurs after the
	first error and before the error flag has been cleared by software will escape recording.

This register contains the address of the 32 byte-aligned data unit on which system memory ECC error(s) was detected.

Bit	Descriptions

31:30	Reserved.

29:1	Error Address Pointer (EAP). This field is used to store address bits A[33:5] of the 32-byte-
	aligned data unit of system memory of which an error (single bit or multi-bit error) has occurred.
	Note: The value of this bit field represents the address of the first single or the first multiple bit
	error occurrence after the error flag bits in the ERRSTS register have been cleared by
	software. A multiple bit error will overwrite a single bit error. Once the error flag bits are set
	as a result of an error, this bit field is locked and does not change as a result of a new error
	until the error flag is cleared by software.

0	Reserved.

58	Intel® 82845 MCH for SDR Datasheet