PCIe to AXI BARs - 4.0 English

QDMA Subsystem for PCI Express Product Guide (PG302)

Document ID
PG302
Release Date
2022-05-20
Version
4.0 English

For each physical function, the PCIe configuration space consists of a set of six 32-bit memory BARs and one 32-bit Expansion ROM BAR. When SR-IOV is enabled, an additional six 32-bit BARs are enabled for each Virtual Function. These BARs provide address translation to the AXI4 memory mapped space capability, interface routing, and AXI4 request attribute configuration. Any pairs of BARs can be configured as a single 64-bit BAR. A programming example can be found in the Address Translation section (Example 3) of AXI Bridge for PCI Express Gen3 Subsystem Product Guide (PG194).

Request Memory Type

The memory type can be set for each PCIe BAR through attributes attr_dma_pciebar2axibar_*_cache_pf*.

  • AxCache[0] is set to 1 for modifiable, and 0 for non-modifiable.
  • AxCache[1] is set to 1 for cacheable, and 0 for non-cacheable.