USB chip is also divided into Controller part and PHY part:
The Controller part mainly realizes the protocol and control of USB. The internal logic is mainly MAC layer, CSR layer and FIFO control layer, and other low power management layers such as:
(1)MAC implements packet packaging and unpacking according to USB protocol, and sends data to PHY according to UTMI bus format (USB3.0 for PIPE).
(2) The CSR layer controls the register. The software controls the USB chip through the CSR register, which interacts with the CPU mainly as a Slave through AXI or AHB.
(3) The FIFO control layer is mainly for data interaction with DDR, and controls the channel through which USB carries data from DDR, mainly for interaction through AXI\/AHB as Master.