Arria V Avalon-ST Interface for PCIe Solutions User Guide

ID 683733
Date 1/04/2023
Public
Document Table of Contents

15.5. Root Port BFM Overview

The basic Root Port BFM provides Verilog HDL task‑based interface to request transactions to issue on the PCI Express link. The Root Port BFM also handles requests received from the PCI Express link. The following figure shows the most important modules in the Root Port BFM.

Figure 76. Root Port BFM

These modules implement the following functionality:

  • BFM Log Interface,altpcietb_bfm_log.v and altlpcietb_bfm_rp_<gen>_x8.v: The BFM log functions provides routine for writing commonly formatted messages to the simulator standard output and optionally to a log file. It also provides controls that stop simulation on errors. For details on these procedures, refer to BFM Log and Message Procedures.
  • BFM Read/Write Request Functions, altpcietb_bfm_rp_<gen>_x8.sv: These functions provide the basic BFM calls for PCI Express read and write requests. For details on these procedures, refer to BFM Read and Write Procedures.
  • BFM Log Interface, altpcietb_bfm_log.v and altlpcietb_bfm_rp_<gen>_x8.v: The BFM log functions provides routine for writing commonly formatted messages to the simulator standard output and optionally to a log file. It also provides controls that stop simulation on errors. For details on these procedures, refer to BFM Log and Message Procedures.
  • BFM Configuration Functions, altpcietb_g3bfm_configure.v : These functions provide the BFM calls to request configuration of the PCI Express link and the Endpoint Configuration Space registers. For details on these procedures and functions, refer to BFM Configuration Procedures.
  • BFM shared memory, altpcietb_g3bfm_shmem_common.v: This modules provides the Root Port BFM shared memory. It implements the following functionality:
    • Provides data for TX write operations
    • Provides data for RX read operations
    • Receives data for RX write operations
    • Receives data for received completions
    Refer to BFM Shared Memory Access Procedures to learn more about the procedures to read, write, fill, and check the shared memory from the BFM driver.
  • BFM Request Interface, altpcietb_g3bfm_req_intf.v: This interface provides the low-level interface between the altpcietb_g3bfm_rdwr and altpcietb_bfm_configure procedures or functions and the Root Port RTL Model. This interface stores a write-protected data structure containing the sizes and the values programmed in the BAR registers of the Endpoint. It also stores other critical data used for internal BFM management. You do not need to access these files directly to adapt the testbench to test your Endpoint application.
  • Avalon‑ST Interfaces, altpcietb_g3bfm_vc_intf_ast_common.v: These interface modules handle the Root Port interface model. They take requests from the BFM request interface and generate the required PCI Express transactions. They handle completions received from the PCI Express link and notify the BFM request interface when requests are complete. Additionally, they handle any requests received from the PCI Express link, and store or fetch data from the shared memory before generating the required completions.