R-tile Avalon® Streaming Intel® FPGA IP for PCI Express* Design Example User Guide

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ID 683544
Date 12/13/2021
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Document Table of Contents
Document Table of Contents x
1. Design Example Description 2. Quick Start Guide 3. R-Tile Avalon® Streaming Intel® FPGA IP for PCI Express* Design Example User Guide Archives 4. Document Revision History for the R-tile Avalon® Streaming Intel FPGA IP for PCI Express Design Example User Guide
1. Design Example Description x
1.1. Credit Initialization Sequence
1.1. Credit Initialization Sequence x
1.1.1. Credit Value Initialization and Return 1.1.2. Credit Distribution
2. Quick Start Guide x
2.1. Directory Structure 2.2. Generating the Design Example 2.3. Simulating the Design Example 2.4. Root Port BFM 2.5. Compiling the Design Example 2.6. Running the Design Example
2.3. Simulating the Design Example x
2.3.1. Testbench
2.3.1. Testbench x
2.3.1.1. Testbench Modules 2.3.1.2. Test Driver Module 2.3.1.3. PIO Design Example
2.4. Root Port BFM x
2.4.1. BFM Memory Map 2.4.2. Configuration Space Bus and Device Numbering 2.4.3. Configuration of Root Port and Endpoint 2.4.4. Issuing Read and Write Transactions to the Application Layer 2.4.5. BFM Procedures and Functions
2.4.5. BFM Procedures and Functions x
2.4.5.1. ebfm_barwr Procedure 2.4.5.2. ebfm_barwr_imm Procedure 2.4.5.3. ebfm_barrd_wait Procedure 2.4.5.4. ebfm_barrd_nowt Procedure 2.4.5.5. ebfm_cfgwr_imm_wait Procedure 2.4.5.6. ebfm_cfgwr_imm_nowt Procedure 2.4.5.7. ebfm_cfgrd_wait Procedure 2.4.5.8. ebfm_cfgrd_nowt Procedure 2.4.5.9. BFM Configuration Procedures 2.4.5.10. BFM Shared Memory Access Procedures 2.4.5.11. BFM Log and Message Procedures 2.4.5.12. Verilog HDL Formatting Functions
2.4.5.9. BFM Configuration Procedures x
2.4.5.9.1. ebfm_cfg_rp_ep Procedure 2.4.5.9.2. ebfm_cfg_decode_bar Procedure
2.4.5.10. BFM Shared Memory Access Procedures x
2.4.5.10.1. Shared Memory Constants 2.4.5.10.2. shmem_write Task 2.4.5.10.3. shmem_read Function 2.4.5.10.4. shmem_display Verilog HDL Function 2.4.5.10.5. shmem_fill Procedure 2.4.5.10.6. shmem_chk_ok Function
2.4.5.11. BFM Log and Message Procedures x
2.4.5.11.1. ebfm_display Verilog HDL Function 2.4.5.11.2. ebfm_log_stop_sim Verilog HDL Function 2.4.5.11.3. ebfm_log_set_suppressed_msg_mask Task 2.4.5.11.4. ebfm_log_set_stop_on_msg_mask Verilog HDL Task 2.4.5.11.5. ebfm_log_open Verilog HDL Function 2.4.5.11.6. ebfm_log_close Verilog HDL Function
2.4.5.12. Verilog HDL Formatting Functions x
2.4.5.12.1. himage1 2.4.5.12.2. himage2 2.4.5.12.3. himage4 2.4.5.12.4. himage8 2.4.5.12.5. himage16 2.4.5.12.6. dimage1 2.4.5.12.7. dimage2 2.4.5.12.8. dimage3 2.4.5.12.9. dimage4 2.4.5.12.10. dimage5 2.4.5.12.11. dimage6 2.4.5.12.12. dimage7
1. Design Example Description
2. Quick Start Guide
3. R-Tile Avalon® Streaming Intel® FPGA IP for PCI Express* Design Example User Guide Archives
4. Document Revision History for the R-tile Avalon® Streaming Intel FPGA IP for PCI Express Design Example User Guide

2.3.1. Testbench

The testbench uses a test driver module, altpcietb_bfm_rp_gen5_x16.sv, to initiate the configuration and memory transactions. At startup, the test driver module displays information from the Root Port and Endpoint Configuration Space registers, so that you can correlate to the parameters you specified using the Parameter Editor.

The example design and testbench are dynamically generated based on the configuration that you choose for the R-tile IP for PCIe. The testbench uses the parameters that you specify in the Parameter Editor in Intel® Quartus® Prime.

This testbench simulates a Gen5 ×16 PCI Express link using the serial PCI Express interface. The following figure presents a high level view of the PIO design example.

Figure 16. PIO Design Example Simulation Testbench
When configured as an Endpoint variation, the testbench instantiates a design example with a R-tile Endpoint and a Root Port BFM containing a second R-tile (configured as a Root Port) to interface with the Endpoint. For more details on this Root Port BFM, refer to Section 2.5: Root Port BFM. The Root Port BFM provides the following functions:

  • A configuration routine that sets up all the basic configuration registers in the Endpoint. This configuration allows the Endpoint application to be the target and initiator of PCI Express transactions.

  • A Verilog HDL procedure interface to initiate PCI Express transactions to the Endpoint.

This testbench simulates the scenario of a single Root Port talking to a single Endpoint.

The testbench uses a test driver module, altpcietb_bfm_rp_gen5_x16.sv, to initiate the configuration and memory transactions. At startup, the test driver module displays information from the Root Port and Endpoint Configuration Space registers, so that you can correlate to the parameters you specified using the Parameter Editor.

Note: The Intel testbench and Root Port BFM provide a simple method to do basic testing of the Application Layer logic that interfaces to the variation. This BFM allows you to create and run simple task stimuli with configurable parameters to exercise basic functionality of the Intel example design. The testbench and Root Port BFM are not intended to be a substitute for a full verification environment. Corner cases and certain traffic profile stimuli are not covered. Refer to the items listed below for further details. To ensure the best verification coverage possible, Intel suggests strongly that you obtain commercially available PCI Express verification IP and tools, in combination with performing extensive hardware testing.
Your Application Layer design may need to handle at least the following scenarios that are not possible to create with the Intel testbench and the Root Port BFM, or are due to the limitations of the example design:

  • It is unable to generate or receive Vendor Defined Messages. Some systems generate Vendor Defined Messages. The Hard IP block simply passes these messages on to the Application Layer. Consequently, you should make the decision, based on your application, whether to design the Application Layer to process them.

  • It can only handle received read requests that are less than or equal to 256 bits or 8 DW. Many systems are capable of handling larger read requests that are then returned in multiple completions.

  • It always returns a single completion for every read request. Some systems split completions on every 64-byte address boundary.
  • It always returns completions in the same order the read requests were issued. Some systems generate the completions out-of-order.

  • It is unable to generate zero-length read requests that some systems generate as flush requests following some write transactions. The Application Layer must be capable of generating the completions to the zero-length read requests.

  • It does not support parity.
  • It does not support multi-function designs.
  • It does not support Single Root I/O Virtualization (SR-IOV).
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