Adaptec 1737100 Programmer Manual - Page 85

Register Descriptions PCI SubSystemVendor ID Register Type: R Internal Registers Subgroup: PCI Configuration Header Byte Address: 2Ch - 2Dh Bit(s) 15:0 Table 7-19. SubSystemVendor ID Register Reset rw Value Description/Function r 9004h SubSystemVendorID[15:0]: The PCI SubSystem Vendor Identifier register helps to identify the vendor of the add-in board even though the PCI controller has been designed by another vendor and has another Vendors ID. The default value is the Adaptec Vendor ID number, 9004h. This value can be changed to a value read from an external serial EEPROM if BR_A1 pin is '1' when PCI_PCIRST_ is deasserted. PCI SubSystem ID Register Type: R Internal Registers Subgroup: PCI Configuration Header Byte Address: 2Eh - 2Fh Bit(s) 15 14:0 Table 7-20. SubSystem ID Register Reset rw Value Description/Function r 0 64-bit Address Space: For Base Address 0 register bit 2. Setting this bit indicates 64-bit address space. Clearing the bit indicates 32-bit address space. r xxxxh SubSystemID: The PCI SubSystem Identifier register provides the vendors of add-in cards a mechanism to distinguish their cards from one another even though the cards may have the same PCI device ID. This value can be changed to a value read from an external serial EEPROM if BR_A1 pin is '1' when PCI_PCIRST_ is deasserted. Refer to Table 7-35 for the possible default values for the SubSystem ID. PCI EXPROMCTL (Expansion ROM Control) Register Type: R/W Internal Registers Subgroup: PCI Configuration Header Byte Address: 30h - 33h The Expansion ROM Base Address register is used to define the base address, maximum size and access enable control of an external ROM which may be used with a PCI device. The PCI supports an external ROM/EEPROM of 256-KBytes. When an access is made with both BASEADR0 and EXROMCTL address defined region overlaps and EXROMEN is active, the PCI responds with a target-abort. 7-13