Specifications
2-42 TLSB Bus
System fatal data bus errors are cumulative. Should a second system fatal
error occur, TLSB_FAULT is asserted a second time. If a fatal error is of a
different type than the first, an additional error is set in the TLBER regis-
ter.
2.4.4.8 Summary of Data Bus Errors
Table 2-12 shows all the data bus errors, which nodes are responsible for
detecting the errors, and what error signals are asserted.
Table 2-12 Data Bus Error Summary
2.4.5 Additional Status
In addition to the error bits in the TLBER and TLESRn registers, addi-
tional status is preserved on detection of errors.
• The TLESRn registers record an error syndrome (SYNDn) and
whether the node transmitted the data that was read with errors
(TDE).
• The TLBER register records which TLESRn registers contain error
status corresponding to a specific error occurrence (DSn).
• The TLBER register records which nodes detected errors on commands
issued by that node (ATDE).
• The TLBER register records which node transmitted the data that re-
sulted in assertion of TLSB_DATA_ERROR (DTDE). Software must
poll all nodes to find it.
• The TLFADRn registers record the address, command, and bank num-
ber from the command. Software must poll all nodes to find the re-
corded data.
These registers can only hold information relative to one error. It is, there-
fore, the responsibility of software to read and clear all error bits and
status. Even when errors occur infrequently there is a chance that a sec-
ond error can occur before software clears all status from a previous error.
The error register descriptions specify the behavior of a node when multi-
ple errors occur.
Error Description Who Detects Signal
UDE
CWDE
CRDE
FDTCE
DCTCE
SEQE
DSE
DTO
Uncorrectable Data Error
Correctable Write Data Error
Correctable Read Data Error
Fatal Data Transmit Check Error
Data Control Transmit Check Error
Sequence Error
Data Status Error
Data Timeout
All participants
All participants
All participants
Transmitter
All participants
All nodes
All participants
Commander
TLSB_DATA_ERROR
TLSB_DATA_ERROR
TLSB_DATA_ERROR
TLSB_FAULT
TLSB_FAULT
TLSB_FAULT
TLSB_FAULT
TLSB_FAULT