Base and limit registers for root ports, Device identification registers for function Page 34
Page 34
Base and Limit Registers for Root Ports
Table 3-9: Base and Limit Registers for Function 0
The following table describes the
Base
and
Limit
registers which are available in the Type 1 Configuration Space
for Root Ports. These registers are used for TLP routing and specify the address ranges assigned to components
that are downstream of the Root Port or bridge.
Parameter
Value
Description
Input/
Output
Disabled
16-bit I/O addressing
32-bit I/O addressing
Specifies the address widths for the
IO base
and
IO
limit
registers.
Prefetchable
memory
Disabled
16-bit memory addressing
32-bit memory addressing
Specifies the address widths for the
Prefetchable
Memory Base
register and
Prefetchable Memory
Limit
register.
Related Information
Device Identification Registers for Function
Table 3-10: Device ID Registers
The following table lists the default values of the read-only Device ID registers. You can use the parameter editor
to change the values of these registers. Refer to Type 0 Configuration Space Registers for the layout of the Device
Identification registers.
Register Name
Range
Default Value
Description
Vendor ID
16 bits
0x00000000
Sets the read-only value of the
Vendor ID
register. This
parameter cannot be set to 0xFFFF, per the PCI Express
Specification.
Address offset: 0x000.
Device ID
16 bits
0x00000001
Sets the read-only value of the
Device ID
register. This
register is only valid in the Type 0 (Endpoint) Configu‐
ration Space.
Address offset: 0x000.
Revision ID
8 bits
0x00000001
Sets the read-only value of the
Revision ID
register.
Address offset: 0x008.
2014.12.15
Base and Limit Registers for Root Ports
3-11
Parameter Settings
Altera Corporation