When Descriptor bypass mode is enabled, the user logic is responsible for making descriptors and transferring them in descriptor bypass interface. The following figure shows AXI4 Memory Mapped design with descriptor bypass mode enabled. You can select which channels will have descriptor bypass mode. When Channel 0 of H2C and Channel 0 C2H are selected for Descriptor bypass mode, the generated Vivado® example design has descriptor bypass ports of H2C0 and C2H0 connected to logic that will generate only one descriptor of 64 bytes. The user is responsible for developing codes for other channels and expanding the descriptor itself.
The following figure shows the AXI-MM example with Descriptor Bypass Mode enabled.