Adaptec 1737100 Programmer Manual - Page 83

Register Descriptions PCI Hdrtype (Header Type) Register Type: R Internal Registers Subgroup: PCI Configuration Header Byte Address: 0Eh Bit(s) rw 7 r 6:0 r Reset Value 0 0 Table 7-13. Header Type Register Description/Function HDRTYPE[7]: The AIC-6915 is a single function device HDRTYPE[6:0]: Always read 0. BIST (Built-in Self Test) Register Type: R Internal Registers Subgroup: PCI Configuration Header Byte Address: 0Fh Bit(s) rw 7:0 r Reset Value 0 Table 7-14. BIST Register Description/Function BIST[7:0]: Always read as 0. PCI LowBASEADR0 (Base Address 0) Register Type: R/W Internal Registers Subgroup: PCI Configuration Header Byte Address: 10h - 13h Note: When an access is made to an address that is mapped and enabled in both the BASEADR0 and EXROMCTL registers, The PCI responds with a target abort. Bit(s) rw 31:19 r/w 18:4 r 3 r 2:1 r 0 r Reset Value 0 0 0 10 0 Table 7-15. Base Address 0 Register Description/Function BASEADR0[31:19]: This field indicates the mapping capability of 512-KBytes of system memory space within the low 32-bit address segment of the 64-bit address space. BASEADR0[18:4]: Indicates address space requirement, Always read as 0. Prefetchable: Always reads 0. Not supported. MemorySpaceAccessType[1:0]: Always read as 10. The AIC-6915 as a target may be located anywhere in a 64-bit address space. Memory Space Indicator: Always reads 0. Note: bit0 =0 indicates that BASEADR0 register is used for mapping into system memory address space. 7-11