PCI-X Interface

Target Terminations Initiated by the 41210

The 41210 responds with a retry to PCI-X when one of the following conditions is met:

A memory read transaction occurs and the 41210 delayed transaction queue is full.

A LOCK transaction is established from PCI Express*-to-PCI.

A memory write transaction occurs and the 41210 has no free buffer space to accept the write.

A memory write is from a master other than the master that was previously retried (starvation prevention mechanism).

Note: The 41210 never retries a completion since it always has enough buffer space for all split requests it sends out. No transaction information is retained on any writes.

Disconnect

The 41210 disconnects a transaction on PCI-X when one of the following conditions is met:

The 41210 cannot accept any more write data and an ADB is reached.

A split completion packet being sent, ADB is reached, and the 41210 read buffers are running dry.

Inverse decode window ends, and an upstream write is in progress, irrespective of the availability of the write-buffer.

Target Abort

The 41210 returns a target abort to PCI-X when one of the following conditions is met:

The initial request received a target-abort on the peer PCI bus or a Completion with Completer Abort status on the PCI Express* interface.

All requests with address parity error and the parity error response bit is set.

Master Abort

The 41210 master aborts all memory transactions on PCI-X when the bus master enable (BME) bit is cleared.

The 41210 returns a master abort response in a split completion when the split cycle master aborted on PCI Express*/peer PCI.

Split Response

All memory read cycles that cross the 41210 receive this termination, if they are not retried.

Intel® 41210 Serial to Parallel PCI Bridge Developer’s Manual

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Intel 41210 manual PCI-X Interface