P-Tile Avalon® Memory-mapped Intel® FPGA IP for PCI Express* User Guide

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ID 683268
Date 7/14/2021
Public
Document Table of Contents
Document Table of Contents x
1. About the P-tile Avalon® Intel® FPGA IPs for PCI Express 2. IP Architecture and Functional Description 3. Parameters 4. Interfaces 5. Advanced Features 6. Troubleshooting/Debugging 7. Document Revision History for the P-tile Avalon® Memory-mapped Intel FPGA IP for PCI Express User Guide A. Configuration Space Registers
1. About the P-tile Avalon® Intel® FPGA IPs for PCI Express x
1.1. Overview 1.2. Features 1.3. Release Information 1.4. Device Family Support 1.5. Performance and Resource Utilization 1.6. IP Core and Design Example Support Levels
2. IP Architecture and Functional Description x
2.1. Top-Level Architecture 2.2. Functional Description
2.1. Top-Level Architecture x
2.1.1. Avalon® -MM Bridge Architecture 2.1.2. Clock Domains 2.1.3. Refclk 2.1.4. Reset
2.2. Functional Description x
2.2.1. PMA/PCS 2.2.2. Data Link Layer Overview 2.2.3. Transaction Layer Overview 2.2.4. Avalon® -MM Bridge
2.2.4. Avalon® -MM Bridge x
2.2.4.1. Endpoint Mode with Data Movers 2.2.4.2. Endpoint Mode 2.2.4.3. Root Port Mode
3. Parameters x
3.1. Top-Level Settings 3.2. Core Parameters 3.3. Avalon-MM Settings
3.2. Core Parameters x
3.2.1. Base Address Registers 3.2.2. PCI Express and PCI Capabilities Parameters 3.2.3. Device Identification Registers 3.2.4. Configuration, Debug and Extension Options
3.2.2. PCI Express and PCI Capabilities Parameters x
3.2.2.1. Device Capabilities 3.2.2.2. Link Capabilities 3.2.2.3. Legacy Interrupt Pin Register 3.2.2.4. MSI Capabilities 3.2.2.5. MSI-X Capabilities 3.2.2.6. Device Serial Number Capability 3.2.2.7. TLP Processing Hints (TPH)
4. Interfaces x
4.1. Overview 4.2. Clocks and Resets 4.3. Avalon® -MM Interface 4.4. Serial Data Interface 4.5. Hard IP Status Interface 4.6. Interrupt Interface 4.7. Hot Plug Interface (RP Only) 4.8. Power Management Interface 4.9. Configuration Output Interface 4.10. Hard IP Reconfiguration Interface 4.11. PHY Reconfiguration Interface
4.2. Clocks and Resets x
4.2.1. Interface Clock Signals 4.2.2. Interface Reset Signals
4.3. Avalon® -MM Interface x
4.3.1. Endpoint Mode Interface (512-bit Avalon® -MM Interface) 4.3.2. Root Port Mode Interface (256-bit Avalon® -MM Interface)
4.3.1. Endpoint Mode Interface (512-bit Avalon® -MM Interface) x
4.3.1.1. Bursting Avalon® -MM Master and Conduit 4.3.1.2. Bursting Avalon® -MM Slave and Conduit 4.3.1.3. Read Data Mover 4.3.1.4. Write Data Mover 4.3.1.5. Descriptor Format for Data Movers 4.3.1.6. Avalon® -MM DMA Operations
4.3.1.1. Bursting Avalon® -MM Master and Conduit x
4.3.1.1.1. Bursting Avalon® -MM Master and Conduit in Non-Bursting Mode
4.3.1.2. Bursting Avalon® -MM Slave and Conduit x
4.3.1.2.1. Bursting Avalon® -MM Slave and Conduit in Non-Bursting Mode
4.3.1.3. Read Data Mover x
4.3.1.3.1. Read Data Mover Avalon® -MM Write Master and Conduit 4.3.1.3.2. Read Data Mover Avalon® -ST Descriptor Sinks 4.3.1.3.3. Read Data Mover Status Avalon® -ST Source
4.3.1.4. Write Data Mover x
4.3.1.4.1. Write Data Mover Avalon® -MM Read Master and Conduit 4.3.1.4.2. Write Data Mover Avalon® -ST Descriptor Sinks 4.3.1.4.3. Write Data Mover Status Avalon® -ST Source
4.3.2. Root Port Mode Interface (256-bit Avalon® -MM Interface) x
4.3.2.1. High Performance Avalon® -MM Slave (HPTXS) Interface 4.3.2.2. High Performance Avalon® -MM Master (HPRXM) Interface 4.3.2.3. 32-Bit Control Register Access (CRA) Slave (Root Port only)
4.6. Interrupt Interface x
4.6.1. Legacy Interrupts 4.6.2. MSI 4.6.3. MSI-X
4.6.3. MSI-X x
4.6.3.1. Implementing MSI-X Interrupts
4.10. Hard IP Reconfiguration Interface x
4.10.1. Address Map for the User Avalon-MM Interface 4.10.2. Configuration Registers Access
4.10.2. Configuration Registers Access x
4.10.2.1. Using Direct User Avalon-MM Interface (Byte Access) 4.10.2.2. Using the Debug Register Interface Access
5. Advanced Features x
5.1. PCIe* Port Bifurcation and PHY Channel Mapping
6. Troubleshooting/Debugging x
6.1. Hardware 6.2. Debug Toolkit
6.1. Hardware x
6.1.1. Debugging Link Training Issues 6.1.2. Debugging Data Transfer and Performance Issues
6.1.1. Debugging Link Training Issues x
6.1.1.1. Generic Tools and Utilities 6.1.1.2. SignalTapII Logic Analyzer 6.1.1.3. Additional Debug Tools
6.1.2. Debugging Data Transfer and Performance Issues x
6.1.2.1. Advanced Error Reporting (AER) 6.1.2.2. Second-Level Debug Tools
6.2. Debug Toolkit x
6.2.1. Overview 6.2.2. Enabling the P-Tile Debug Toolkit 6.2.3. Launching the P-Tile Debug Toolkit 6.2.4. Using the P-Tile Debug Toolkit 6.2.5. Enabling the P-Tile Link Inspector 6.2.6. Using the P-Tile Link Inspector
A. Configuration Space Registers x
A.1. Configuration Space Registers A.2. Intel-Defined VSEC Capability Registers
A.1. Configuration Space Registers x
A.1.1. Register Access Definitions A.1.2. PCIe Configuration Header Registers A.1.3. PCI Express Capability Structures A.1.4. Physical Layer 16.0 GT/s Extended Capability Structure A.1.5. MSI-X Registers
A.2. Intel-Defined VSEC Capability Registers x
A.2.1. Intel-Defined VSEC Capability Header (Offset 00h) A.2.2. Intel-Defined Vendor Specific Header (Offset 04h) A.2.3. Intel Marker (Offset 08h) A.2.4. JTAG Silicon ID (Offset 0x0C - 0x18) A.2.5. User Configurable Device and Board ID (Offset 0x1C - 0x1D) A.2.6. General Purpose Control and Status Register (Offset 0x30) A.2.7. Uncorrectable Internal Error Status Register (Offset 0x34) A.2.8. Uncorrectable Internal Error Mask Register (Offset 0x38) A.2.9. Correctable Internal Error Status Register (Offset 0x3C) A.2.10. Correctable Internal Error Mask Register (Offset 0x40)
1. About the P-tile Avalon® Intel® FPGA IPs for PCI Express
2. IP Architecture and Functional Description
3. Parameters
4. Interfaces
5. Advanced Features
6. Troubleshooting/Debugging
7. Document Revision History for the P-tile Avalon® Memory-mapped Intel FPGA IP for PCI Express User Guide
A. Configuration Space Registers

4.6.2. MSI

If MSI or MSI-X are enabled at IP configuration time, the external interrupt controller can generate MSI/MSI-X transactions by issuing memory writes to the Bursting Slave or using the immediate write feature of the Write Data Mover, especially if signaling the completion of a DMA transfer by the Write Data Mover. The interrupt controller gets the address and data information to generate the MSI/MSI-X messages from the MSI or MSI-X capability registers in the Transaction Layer in the P-Tile IP.

MSI interrupts are signaled on the PCI Express link using a single dword Memory Write TLP. The user application issues an MSI request (MWr) through the Avalon® -ST interface and updates the configuration space register using the MSI interface.

For more details on the MSI Capability Structure, refer to Figure 55.

The Mask Bits register and Pending Bits register are 32 bits in length each, with each potential interrupt message having its own mask bit and pending bit. If bit[0] of the Mask Bits register is set, interrupt message 0 is masked. When an interrupt message is masked, the MSI for that vector cannot be sent. If software clears the mask bit and the corresponding pending bit is set, the function must send the MSI request at that time.

You should obtain the necessary MSI information (such as the message address and data) from the configuration output interface (tl_cfg_*) to create the MWr TLP in the format shown below to be sent via the Avalon® -ST interface.

Figure 21. Creating a MWr TLP for an MSI Request
Table 46.  MSI Pending Bits Interface
Signal Name Direction Description Clock Domain EP/RP
msi_pnd_func_i[2:0] I Function number select for the Pending Bits register in the MSI capability structure. p<n>_app_clk EP
msi_pnd_addr_i[1:0] I Byte select for Pending Bits Register in the MSI Capability Structure. For example if msi_pnd_addr_i[1:0] = 00, bits [7:0] of the Pending Bits register will be updated with msi_pnd_byte_i[7:0]. If msi_pnd_addr_i[1:0] = 01, bits [15:8] of the Pending Bits register will be updated with msi_pnd_byte_i[7:0]. p<n>_app_clk EP
msi_pnd_byte_i[7:0] I Indicate that function has a pending associated message. p<n>_app_clk EP

The following figure shows the timings of msi_pnd_* signals in three scenarios. The first scenario shows the case when the MSI pending bits register is not used. The second scenario shows the case when only physical function 0 is enabled and the MSI pending bits register is used. The last scenario shows the case when four physical functions are enabled and the MSI pending bits register is used.

Figure 22. Example Timing Diagrams for msi_pnd* Signals

There are 32 possible MSI messages. The number of messages requested by a particular component does not necessarily correspond to the number of messages allocated. For example, in the following figure, the Endpoint requests eight MSIs but is only allocated two. In this case, you must design the Application Layer to use only two allocated messages.

Figure 23. MSI Request Example

The following table describes three example implementations. The first example allocates all 32 MSI messages. The second and third examples only allocate 4 interrupts.

Table 47.  MSI Messages Requested, Allocated, and Mapped

MSI

Allocated

32

4

4

System Error

31

3

3

Hot Plug and Power Management Event

30

2

3

Application Layer

29:0

1:0

2:0

MSI interrupts generated for Hot Plug, Power Management Events, and System Errors always use Traffic Class 0. MSI interrupts generated by the Application Layer can use any Traffic Class. For example, a DMA that generates an MSI at the end of a transmission can use the same traffic control as was used to transfer data.

The following figure illustrates a possible implementation of the Interrupt Handler Module with a per vector enable bit in the Application Layer. Alternatively, the Application Layer could implement a global interrupt enable instead of this per vector MSI.

Figure 24. Example Implementation of the Interrupt Handler Block
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