Visible to Intel only — GUID: tlg1685642823294
Ixiasoft
Visible to Intel only — GUID: tlg1685642823294
Ixiasoft
2.1.2. USB 3.1 AxADDR width is limited to 32-bit
Description
The USB 3.1 controller is limited to an AXI address width of 32-bits, and therefore, can only access up to 4 GBytes of system memory address space.
Workaround
If your application needs to access address space larger than 4 GBytes, such as the 256 GByte address space of the HPS-to-FPGA bridge, then SMMU needs to reprogram to allocate different 4 GByte of address space in system memory compared to earlier allocation. Overall, USB data processing will be slower due to SMMU reprogramming overhead.