Self configuration of the Actor SBCs occurs while the Director SBC is busy configuring the PCI bus and other PCI modules. As alluded to earlier the Actor SBCs must wait for the Director SBC to complete the configuration of the PCI bus before trying to use the LCB. A mechanism to do this is described in Section 1.5.2.
Each SBC requires access to a specific portion of the LCB PCI I/O and Memory spaces, see Section 1.6. In order to prevent the SBCs from mapping conflicting portions of the PCI memory space the SBCs must be enumerated. The SBCs are enumerated by using the slot position in the cPCI crate. The SBCs are enumerated in increasing order according to PCI slot position.
Given the opening assumption that the SBCs are homegeneous allows all the SBCs to map the PCI memory in a uniform fashion. Additionally this assumption allows the Director SBC to configure the LCB on behalf of the Actor SBCs, i.e. the Actor SBCs do not need to configure the LCB in order to enable the LCB. This significantly aids in the syncronization of the LCB and SBC configuration.