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1. About the R-tile Avalon® Streaming Intel® FPGA IP for PCI Express
2. IP Architecture and Functional Description
3. Advanced Features
4. Interfaces
5. Parameters
6. Troubleshooting/Debugging
7. R-Tile Avalon® Streaming Intel® FPGA IP for PCI Express* User Guide Archives
8. Document Revision History for the R-tile Avalon® Streaming Intel FPGA IP for PCI Express User Guide
A. Configuration Space Registers
B. Root Port Enumeration
C. Implementation of Address Translation Services (ATS) in Endpoint Mode
D. Packets Forwarded to the User Application in TLP Bypass Mode
3.2.2.5.1. VirtIO Common Configuration Capability Register (Address: 0x012)
3.2.2.5.2. VirtIO Common Configuration BAR Indicator Register (Address: 0x013)
3.2.2.5.3. VirtIO Common Configuration BAR Offset Register (Address: 0x014)
3.2.2.5.4. VirtIO Common Configuration Structure Length Register (Address 0x015)
3.2.2.5.5. VirtIO Notifications Capability Register (Address: 0x016)
3.2.2.5.6. VirtIO Notifications BAR Indicator Register (Address: 0x017)
3.2.2.5.7. VirtIO Notifications BAR Offset Register (Address: 0x018)
3.2.2.5.8. VirtIO Notifications Structure Length Register (Address: 0x019)
3.2.2.5.9. VirtIO Notifications Notify Off Multiplier Register (Address: 0x01A)
3.2.2.5.10. VirtIO ISR Status Capability Register (Address: 0x02F)
3.2.2.5.11. VirtIO ISR Status BAR Indicator Register (Address: 0x030)
3.2.2.5.12. VirtIO ISR Status BAR Offset Register (Address: 0x031)
3.2.2.5.13. VirtIO ISR Status Structure Length Register (Address: 0x032)
3.2.2.5.14. VirtIO Device Specific Capability Register (Address: 0x033)
3.2.2.5.15. VirtIO Device Specific BAR Indicator Register (Address: 0x034)
3.2.2.5.16. VirtIO Device Specific BAR Offset Register (Address 0x035)
3.2.2.5.17. VirtIO Device Specific Structure Length Register (Address: 0x036)
3.2.2.5.18. VirtIO PCI Configuration Access Capability Register (Address: 0x037)
3.2.2.5.19. VirtIO PCI Configuration Access BAR Indicator Register (Address: 0x038)
3.2.2.5.20. VirtIO PCI Configuration Access BAR Offset Register (Address: 0x039)
3.2.2.5.21. VirtIO PCI Configuration Access Structure Length Register (Address: 0x03A)
3.2.2.5.22. VirtIO PCI Configuration Access Data Register (Address: 0x03B)
4.3.1. Avalon® Streaming Interface
4.3.2. Precision Time Measurement (PTM) Interface (Endpoint Only)
4.3.3. Interrupt Interface
4.3.4. Hard IP Reconfiguration Interface
4.3.5. Error Interface
4.3.6. Completion Timeout Interface
4.3.7. Configuration Intercept Interface
4.3.8. Power Management Interface
4.3.9. Hard IP Status Interface
4.3.10. Page Request Services (PRS) Interface (Endpoint Only)
4.3.11. Function-Level Reset (FLR) Interface (Endpoint Only)
4.3.12. SR-IOV VF Error Flag Interface (Endpoint Only)
4.3.13. General Purpose VSEC Interface
5.2.3.1. Device Capabilities
5.2.3.2. VirtIO Parameters
5.2.3.3. Link Capabilities
5.2.3.4. Legacy Interrupt Pin Register
5.2.3.5. MSI Capabilities
5.2.3.6. MSI-X Capabilities
5.2.3.7. Slot Capabilities
5.2.3.8. Latency Tolerance Reporting (LTR)
5.2.3.9. Process Address Space ID (PASID)
5.2.3.10. Device Serial Number Capability
5.2.3.11. Page Request Service (PRS)
5.2.3.12. Access Control Service (ACS)
5.2.3.13. Power Management
5.2.3.14. Vendor Specific Extended Capability (VSEC) Registers
5.2.3.15. TLP Processing Hints (TPH)
5.2.3.16. Address Translation Services (ATS) Capabilities
5.2.3.17. Precision Time Management (PTM)
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4.3.3.3.1. Implementing MSI-X Interrupts
Section 6.8.2 of the PCI Local Bus Specification describes the MSI-X capability and table structures. The MSI-X capability structure points to the MSI-X Table structure and MSI-X Pending Bit Array (PBA) registers. The BIOS sets up the starting address offsets and BAR associated with the pointer to the starting address of the MSI-X Table and PBA registers.
MSI-X Interrupt Components
- Host software sets up the MSI-X interrupts in the Application Layer by completing the following steps:
- Host software reads the Message Control register at 0x050 register to determine the MSI-X Table size. The number of table entries is the <value read> + 1.
The maximum table size is 2048 entries. Each 16-byte entry is divided in 4 fields as shown in the figure below. The MSI-X table can be accessed on any BAR configured. The base address of the MSI-X table must be aligned to a 4 KB boundary.
- The host sets up the MSI-X table. It programs MSI-X address, data, and masks bits for each entry as shown in the figure below.
Figure 33. Format of MSI-X Table
- The host calculates the address of the <n th > entry using the following formula:
nth_address = base address[BAR] + 16<n>
- Host software reads the Message Control register at 0x050 register to determine the MSI-X Table size. The number of table entries is the <value read> + 1.
- When Application Layer has an interrupt, it drives an interrupt request to the IRQ Source module.
- The IRQ Source sets appropriate bit in the MSI-X PBA table.
The PBA can use qword or dword accesses. For qword accesses, the IRQ Source calculates the address of the <m th > bit using the following formulas:
qword address = <PBA base addr> + 8(floor(<m>/64)) qword bit = <m> mod 64
Figure 34. MSI-X PBA Table - The IRQ Processor reads the entry in the MSI-X table.
- If the interrupt is masked by the Vector_Control field of the MSI-X table, the interrupt remains in the pending state.
- If the interrupt is not masked, IRQ Processor sends Memory Write Request to the TX slave interface. It uses the address and data from the MSI-X table. If Message Upper Address = 0, the IRQ Processor creates a three-dword header. If the Message Upper Address > 0, it creates a 4-dword header.
- The host interrupt service routine detects the TLP as an interrupt and services it.