Intel 460GX Software Developer’s Manual page 129

(DPE) bit is asserted. Regardless, if the transaction is a read, the PCISTS register's Parity Error
(PE) bit will be set. Additionally, address, command, and data related information is logged in the
FEPCIAL and FEPCIL registers if the error is the first error observed by the WXB.
6.12.8.1.6 Other Violations
The PCI specification identifies numerous cases that are violations of the PCI protocol. Other than
the cases identified above, the WXB makes no attempt to check for such violations. Response to
such violations is undefined. Refer to the PCI specification for a complete description of the
required PCI protocol.
6.12.8.2 WXB as Target
6.12.8.2.1 Illegal PCI Request Type
The WXB will not claim transactions that use an illegal or unrecognized request type.
6.12.8.2.2 Target Disconnect
The WXB will issue a target disconnect under the following circumstances:
•
After the first data transfer if the transaction is using an unrecognized addressing mode (the
WXB will only support linear incrementing as a target),
•
On reads, when no more data is available in the read buffers, and
These conditions are not treated as an error, and will not be logged or reported.
6.12.8.2.3 Target Retry
The WXB will issue a target retry when:
•
A read request is to an address that has already been accepted as a delayed transaction (i.e. the
request is already being serviced, but data has not arrived).
•
A read request to this address has not yet been accepted by the WXB as a delayed transaction,
there is room to enqueue a new delayed transaction, and the request is enqueued.
•
A read request is to an address that has not yet been accepted by the WXB and there is no more
room to enqueue a new delayed transaction.
•
A write request has insufficient buffering in the WXB to allow it to be posted (e.g. a full line is
not available for MWI).
•
The PCI interface is LOCKED from the host side, unless the transaction is a read request and
the data has already been fetched by the WXB.
6.12.8.2.4 Target Abort
The WXB will issue a target abort if a hard fail response is returned over the Expander bus. This
response is limited to inbound read requests.
6.12.8.2.5 Other Violations
The PCI specification identifies numerous cases that are violations of the PCI protocol. Other than
the cases identified above, the WXB makes no attempt to check for such violations. Response to
such violations is undefined. This includes, but is not limited to:
Intel® 460GX Chipset Software Developer's Manual
Data Integrity and Error Handling
6-31