Method for verification of PCI-X Planar Speeds
Original Publication Date: 2002-Oct-28
Included in the Prior Art Database: 2003-Jun-21
A method is disclosed that will verify peripheral component interconnect (PCI)-X planar speeds to ensure planars are accurately manufactured. PCI-X planars need to ensure that once built have achieved the targeted speeds and modes as expected. Server platforms are now shipping with PCI connectors that support both PCI-X and PCI modes of operation. In addition there are different speeds on both modes that the adapter will specify. This method determines whether a PCI-X adapter is not just functioning but rather whether it is functioning in the right mode and correct speed. This allows the early detection of planar and/or design problems. Problems have been encountered in the past were the adapter is functioning but not in the correct mode/speed. This method involves adding firmware to read the device and vendor ID of the adapter and checking the adapter current state with a lookup table of adapter speeds and modes. PCI vs PCI-X is controlled by the setting of a PCI connector signal name PCI-X Capable. The distinction between PCI 33 MHz vs PCI 66 MHz and PCI-X 133 MHz vs PCI-X 66 is based on a PCI connector signal M66 Enable.The firmware after reading the value in the adapter/bridge can then report back to the system what signal is broken based on what values was read versus the expected value. For example, an adapter running in PCI 66 MHz which should have been PCI 33 MHz indicates that M66 Enable signal is open on the planars. Similarly, if an adapter is supposed to be at PCI-X 133 MHz but instead is running in PCI 66 MHz then the PCI-X Capable signal is grounded on the planar. This method allows users of PCI-X planars to not just work functionally but also to ensure performance/speeds of the adapters.