An error correction code mechanism for the extensions to the peripheral component
interconnect bus system (PCI-X) used in computer systems is fully backward compatible
with the full PCI protocol. The error correction code check-bits can be inserted
to provide error correction capability for the header address and attribute phases,
as well as for burst and DWORD transaction data phases. The error correction code
check-bits are inserted into unused attribute, clock phase, reserved, or reserved
drive high portions of the AD and/or C/BE# lanes of the PCI-X phases.