Compaq ProLiant 1000 PCI Bus Numbering in a Microsoft Windows NT Environment - Page 44

PCI Bus Numbering in a Microsoft Windows NT Environment 44 Configuration A: Test 1 - Initial Configuration Even though PCI bus numbers are assigned during every boot process, the assignment is exactly the same as long as the configuration remains the same. This bus number and controller discovery test was performed on a simple configuration in a dual-peer PCI ProLiant 6500 server (see Table 13). This configuration is described as simple because it contains only two nonbridged PCI network controllers. Table 13. PCI BIOS bus detection in a ProLiant 6500 - before adding a bridged controller Bus Detection Order/ Controller Discovery 1st Slot Number Primary Bus (0) PCI Bridge/ Controller Type - Test 1 Host to PCI Bus Bridge Bus Number Assignment Bus 0 2nd Slot 1 Netelligent Bus 0 10/100 TX 3rd Slot 2 Empty N/A 4th Seconda Host to PCI Bus Bus 1 ry Bus Bridge (1) 5th Slot 3 Empty N/A 6th Slot 4 Netelligent Bus 1 10/100 TX 7th Slot 5 Empty N/A 8th Slot 6 Empty N/A 9th Slot 7 Empty N/A 10th Slot 8 Empty N/A Description of PCI BIOS Discovery Process The PCI BIOS discovers the Primary Bus and assigns it bus 0. PCI BIOS detects a NIC (no PCI bridge) in slot 1, it is assigned the same bus number as the PCI Bus where it resides, and is the first controller detected by the PCI BIOS. Discovery process continues to PCI slot 2. No PCI controller detected, no bus number assigned. The PCI BIOS discovers the Secondary Bus and increments the bus number to 1. Discovery process continues to PCI slot 3. No PCI controller detected no bus number assigned. PCI BIOS detects a NIC (no PCI bridge) in slot 4 it is assigned the same bus number as the PCI Bus where it resides, bus 1. Discovery process continues to PCI slot 5. No PCI controller detected, no bus number assigned. Discovery process continues to PCI slot 6. No PCI controller detected, no bus number assigned. Discovery process continues to PCI slot 7. No PCI controller detected, no bus number assigned. Discovery process continues to PCI slot 8. No PCI controller detected, no bus number assigned. Reviewing the Test 1 Configuration In Test 1, the PCI BIOS begins the discovery process by identifying buses on the Primary PCI Bus. It continues to the Secondary PCI Bus looking for PCI buses and or bridges. As each bus is detected it is assigned a bus number starting at bus 0, the PCI BIOS then assigns bus numbers to 13UK-1200A-WWEN