Address translations for AXI address is done based on BDF table
programming (0x2420 to 0x2434). These BDF table entries can be programmed through
the AXI4-Lite Slave CSR interface, s_axil_csr_*
.
There are 8 windows provided similar to 8 BARs on PCIe bus. Each entry in BDF table
programming represents one window. If a user needs 2 windows then 2 entrees needs to
be programmed and so on.
There are some restrictions in programming BDF table.
- All PCIe slave bridge data transfers must be quiesced before programming the BDF table.
- There are six registers for each BDF table entry. All six registers must be programmed to make a valid entry. Even if some registers have 0s, you need to program 0s in those registers.
- All the six registers need to be programmed in an order for an
entry to be valid. Order is listed below.
- 0x2420
- 0x2424
- 0x2428
- 0x242C
- 0x2430
- 0x2434
BDF table entree start address = 0x2420 + (0x20 * i), where i = table entree number.