Altera PCI Compiler - Manual (Page 114)

3–40 User Guide Version 11.1 Altera Corporation
PCI Compiler October 2011
Configuration Registers
CardBus CIS Pointer Register
The card information structure (CIS) pointer register is a 32-bit read-only
register that points to the beginning of the CIS. This optional register is
used by devices that have the PCI and CardBus interfaces on the same
silicon. By default, the PCI MegaCore functions do not enable this
register. The CIS Pointer register can be enabled and the register’s value
can be set through the wizard.
Table 3–25 shows this register’s format. For
more information on the CardBus CIS pointer register, refer to the PC
Card Standard Specification, Version 2.10.
Subsystem Vendor ID Register
Subsystem vendor ID is a 16-bit read-only register that identifies add-in
cards from different vendors that have the same functionality. The value
of this register is assigned by the PCI SIG. Refer to
Table 3–26 . The default
value of the subsystem vendor ID register is 0x0000. However, you can
change the value through the wizard.
Table 3–25. CIS Pointer Register Format
Data Bit Mnemonic Read/Write Definition
2..0 adr_space_ind Read Address space indicator. The value of these bits indicates
that the CIS pointer register is pointing to one of the
following spaces: configuration space, memory space, or
expansion ROM space.
The PCI MegaCore functions do not support the condition
where the CIS pointer register points to the configuration
space.
27..3 adr_offset Read Address space offset. This value gives the address
space’s offset indicated by the address space indicator.
31..28 rom_im Read ROM image. These bits are the uppermost bits of the
address space offset when the CIS pointer register is
pointing to an expansion ROM space.
Table 3–26. Subsystem Vendor ID Register Format
Data Bit Mnemonic Read/Write Definition
15..0 sub_ven_id Read PCI subsystem/vendor ID