Visible to Intel only — GUID: nik1410564829093
Ixiasoft
Visible to Intel only — GUID: nik1410564829093
Ixiasoft
4.2. Base Address Register (BAR) and Expansion ROM Settings
The type and size of BARs available depend on port type.
Parameter |
Value |
Description |
---|---|---|
Type |
Disabled 64-bit prefetchable memory 32-bit non-prefetchable memory 32-bit prefetchable memory I/O address space |
If you select 64-bit prefetchable memory, 2 contiguous BARs are combined to form a 64-bit prefetchable BAR; you must set the higher numbered BAR to Disabled. A non-prefetchable 64‑bit BAR is not supported because in a typical system, the Root Port Type 1 Configuration Space sets the maximum non‑prefetchable memory window to 32 bits. The BARs can also be configured as separate 32‑bit memories. Defining memory as prefetchable allows contiguous data to be fetched ahead. Prefetching memory is advantageous when the requestor may require more data from the same region than was originally requested. If you specify that a memory is prefetchable, it must have the following 2 attributes:
|
Size |
16 Bytes–8 EB |
Supports the following memory sizes:
|
Expansion ROM |
Disabled–16 MB |
Specifies the size of the optional ROM. The expansion ROM is only available for the Avalon‑ST interface. |