Embedded Peripherals IP User Guide

ID 683130
Date 10/24/2025
Public
Document Table of Contents
1. Introduction 2. Avalon® -ST Serial Peripheral Interface Core 3. SPI Core 4. SPI Agent/JTAG to Avalon® Host Bridge Cores 5. Intel eSPI Agent Core 6. eSPI to LPC Bridge Core 7. Ethernet MDIO Core 8. Intel FPGA 16550 Compatible UART Core 9. UART Core 10. Lightweight UART Core 11. JTAG UART Core 12. Intel FPGA Avalon® Mailbox Core 13. Intel FPGA Avalon® Mutex Core 14. Intel FPGA Avalon® I2C (Host) Core 15. Intel FPGA I2C Agent to Avalon® -MM Host Bridge Core 16. EPCS/EPCQA Serial Flash Controller Core 17. Intel FPGA Serial Flash Controller Core 18. Intel FPGA Serial Flash Controller II Core 19. Intel FPGA Generic QUAD SPI Controller Core 20. Intel FPGA Generic QUAD SPI Controller II Core 21. Interval Timer Core 22. Intel FPGA Avalon FIFO Memory Core 23. On-Chip Memory (RAM and ROM) Intel FPGA IP 24. On-Chip Memory II (RAM or ROM) Intel FPGA IP 25. PIO Core 26. PLL Cores 27. DMA Controller Core 28. Modular Scatter-Gather DMA Core 29. Scatter-Gather DMA Controller Core 30. Video Sync Generator and Pixel Converter Cores 31. Intel FPGA Interrupt Latency Counter Core 32. Performance Counter Unit Core 33. Vectored Interrupt Controller Core 34. System ID Peripheral Core 35. Intel FPGA GMII to RGMII Converter Core 36. HPS GMII to RGMII Adapter IP 37. Intel FPGA MII to RMII Converter Core 38. HPS GMII to TSE 1000BASE-X/SGMII PCS Bridge Core IP 39. Intel FPGA HPS EMAC to Multi-rate PHY GMII Adapter Core 40. Intel FPGA MSI to GIC Generator Core 41. Cache Coherency Translator IP 42. Altera ACE5-Lite Cache Coherency Translator

40.3. Feature Description

The Intel FPGA MSI-to-GIC Generator provides storage for the MSI system-specified data value. It also generates level interrupt output when there is an unread entry. The following figure illustrates the connection of the MSI-to-GIC Generator module in a PCIe subsystem.
Figure 170. MSI-to-GIC Generator in PCIe RP system

This module is connected to RP_Master of PCIe RootPort HIP issuing memory map write transaction upon MSI TLP arrival. System-specified data value carried by the MSI TLP is written into the module storage. The same Avalon® MM Data Agent port also connects to the host processor for MSI data retrieval upon interrupt assertion. An Intel FPGA MSI-to-GIC Generator module could contain data storage from one to 32 words of continuous address span. Each data word of storage is associated with a corresponding numbered bit of Status Bits and Mask Bits registers. Each data word address location can store up to 32 entries.

There is an up to 32-bit Status Register that indicates which storage word location has an unread entry. Also, there is a similar bit size of Interrupt Mask Register that is in place to allow control of module behavior by the host processor. The Interrupt Mask register provides flexibility for the host processor to disregard the incoming interrupt.

The base address assigned for Intel FPGA MSI-to-GIC Generator module in the subsystem should cover the system-specified message address of MSI capable functions during device configuration. Multiple Intel FPGA MSI-to-GIC Generator modules could be instantiated in a subsystem to cover different system-specified message addresses.

Avalon® -MM Agent interfaces of this module honors fixed latency of access to ensure the connected host (in this case, the RP_Master) can successfully write into the module without back pressure. This avoids the PCIe upstream traffic from impact because of backpressuring of RP_Master.

Since MSI is multiple messages capable and multiple vectors are supported by each MSI capable function, there is a tendency that a system-specified message address receives more than one MSI message data before the host processor is able to service the MSI request. The Component is configurable to have each data word address to receive up to 32 entries, before any data value is retrieved. When you reach the maximum data value entry of 32, subsequent write transactions are dropped and logged. This ensures every write transaction to the storage has no back pressure which may lead to system lock up.