Avago Technologies LSI8751D - Manual (Page 75)

Configuration Registers 3-11
3.3 Configuration Registers
The Configuration registers are accessible only by the system BIOS
during PCI configuration cycles. The lower 128 bytes hold configuration
data while the upper 128 bytes hold the LSI53C875 operating registers,
which are described in
Chapter 5, “SCSI Operating Registers.” These
registers are accessed by SCRIPTS or the host processor, if necessary.
Note: The configuration register descriptions provide general
information only, to indicate which PCI configuration
addresses are supported in the LSI53C875. For detailed
information, refer to the PCI Specification.
Table 3.2 shows the PCI configuration registers implemented by the
LSI53C875/875E.
All PCI-compliant devices, such as the LSI53C875, must support the
Vendor ID , Device ID , Command , and Status registers. Support of other
PCI-compliant registers is optional. In the LSI53C875, registers that are
not supported are not writable and returns all zeros when read. Only
those registers and bits that are currently supported by the LSI53C875
are described in this chapter. For more detailed information on PCI
registers, please see the PCI Specification.