If I instantiate the Altera PCI core in Host-Bridge mode, why is bit-0 of the PCI address bus ad[1:0] set to 1 instead of 0 during configuration accesses?

Description

PCI™-to-PCI bridges use header type 1 transactions, while all other devices used header type 0, including the Altera® PCI MegaCore functions.

Resolution

During the address phase of configuration writes, ad[1:0] are set to "01" for header type 1 and to "00" for header type 0.