Intel SE7520JR2 manual Device Number and Idsel Mapping

Functional Architecture Intel® Server Board SE7520JR2

hierarchical PCI bus under the current bridge. The PCI bus number and the subordinate PCI bus number are the same in the last hierarchical bridge.

3.4.1.7Device Number and IDSEL Mapping

Each device under a PCI bridge has its IDSEL input connected to one bit out of the PCI bus address/data signals AD[31::11] for the PCI bus. Each IDSEL-mapped AD bit acts as a chip select for each device on PCI. The host bridge responds to a unique PCI device ID value that, along with the bus number, cause the assertion of IDSEL for a particular device during configuration cycles. The following table shows the correspondence between IDSEL values and PCI device numbers for the PCI bus. The lower five bits of the device number are used in CONFIG_ADDRESS bits [15::11].

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