The block diagram of PCIe subsystem is shown in Figure 12-1261. The subsystem comprises of these major components – the PCIe Core with AXI interfaces, bridges to connect to the system CBASS0 interconnect master and slave interfaces, bridges to connect the system CBASS0 configuration interfaces, additional logic to implement the Precision Time Measurement (PTM), user configuration and interrupt, and RAMs to support the controller FIFOs.
Figure 12-1261 also shows some example data flows in the PCIe subsystem, such as:
- A remote master issues a read or write access over PCIe to the local device. This will create a command to be issued on the PCIe VBUSM master read or write interface.
- A master in the local device issues a read or write access over PCIe to the remote device. This will create a command to be issued on the PCIe VBUSM slave read or write interface.
- A remote endpoint issues an Address Translation Request (ATS). This will create an inbound transaction on the AXI DTI interface.
- A master in the local device wants to access the local PCIe configuration registers, the ECC aggregator registers or the CPTS registers. This will create a transaction over the PCIe VBUSP slave interface.