Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
67
Address Translation Unit (PCI-X)—Intel
®
81341 and 81342
• When operating in the PCI-X mode, once a split completion transaction has started,
it continues until one of the following is true:
— The requester (now the target) generates a Retry Termination, or a
Disconnection at Next ADB (when the requester is a bridge)
— The byte count is satisfied.
— An internal bus Target Abort was detected. The ATU generates a Split
Completion Message (message class=2h - completer error, and message
index=81h - internal bus target abort) to inform the requester about the
abnormal condition. The ITQ for this transaction is flushed. Refer to
— An internal bus Master Abort was detected. The ATU generates a Split
Completion Message (message class=2h - completer error, and message
index=80h - Master abort) to inform the requester about the abnormal
condition. The ITQ for this transaction is flushed. Refer to
• When operating in the conventional PCI mode, when the master inserts wait states
on the PCI bus, the ATU PCI slave interface waits with no premature disconnects.
• When an uncorrectable data error occurs signified by
PERR#
asserted from the
initiator, no action is taken by the target interface. Refer to
.
• When operating in the conventional PCI mode, when the read on the internal bus is
target-aborted, either a target-abort or a disconnect with data is signaled to the
initiator. This is based on the ATU ECC Target Abort Enable bit (bit 0 of the ATUIMR
for ATU). When set, a target abort is used, when clear, a disconnect is used.
• When operating in the PCI-X mode, when the transaction on the internal bus
resulted in a target abort, the ATU generates a Split Completion Message (message
class=2h - completer error, and message index=81h - internal bus target abort) to
inform the requester about the abnormal condition. The ITQ for this transaction is
flushed. Refer to
.
• When operating in the conventional PCI mode, when the transaction on the internal
bus resulted in a master abort, the ATU returns a target abort to inform the
requester about the abnormal condition. The ITQ for this transaction is flushed.
• When operating in the PCI-X mode, when the transaction on the internal bus
resulted in a master abort, the ATU generates a Split Completion Message
(message class=2h - completer error, and message index=80h - internal bus
master abort) to inform the requester about the abnormal condition. The ITQ for
this transaction is flushed. Refer to
• When operating in the PCI-X mode, when the Split Completion transaction
completes with either Master-Abort or Target-Abort, the requester is indicating a
failure condition that prevents it from accepting the completion it requested. In this
case, since the Split Request addresses a location that has no read side effects, the
ATU must discard the Split Completion and take no further action.