
S875WP1-E TPS
Error Reporting and Handling
Revision 4.0
87
8.1.3
Single-Bit ECC Error Throttling Prevention
The system detects, corrects, and logs correctable errors as long as these errors occur
infrequently, the system should continue to operate without a problem.
Occasionally, correctable errors are caused by a persistent failure of a single component.
Although these errors are correctable, continual calls to the error logger can throttle the system,
preventing further useful work.
For this reason, the system counts certain types of correctable errors and disables reporting if
errors occur too frequently. Error correction remains enabled, but calls to the error handler are
disabled. This allows the system to continue running, despite a persistent correctable failure.
The BIOS adds an entry to the event log to indicate that logging for that type of error has been
disabled. This entry indicates a serious hardware problem that must be repaired at the earliest
possible time.
The system BIOS implements this feature for correctable bus errors. If ten errors occur within 30
minutes, the corresponding error handler disables further reporting of that type of error. The
BIOS re-enables logging and SMIs the next time the system is rebooted.
8.1.4
Memory Bus Errors
The MCH is programmed to flag and log single-bit errors (SBEs) and multi-bit errors (MBEs).
The MCH then triggers an SMI to the ICH5-R and the ICH5-R asserts the SMI# signal. BIOS
then logs the errors in the event log.
8.2 BIOS Error Messages, POST Codes, and BIOS Beep Codes
The BIOS indicates the current testing phase during POST by writing a hex code to I/O location
80h. If errors are encountered, error messages or codes will either be displayed to the video
screen, or if an error has occurred prior to video initialization, errors will be reported through a
series of audio beep codes. POST errors are logged in to the SEL.
The error codes are defined by Intel and, whenever possible, are backward compatible with
error codes used on earlier platforms.