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

12.3.1. Component Interface

Intel FPGA Avalon® Mailbox (simple) component consists of two Avalon® -MM Agent interfaces, one dedicated for each processor. The Mailbox also provides active high level interrupt output, which is served as message arrival notification to the receiving processor. Optionally, a secondary IRQ is created as notification to the message sender indicating if Mailbox is available for incoming message.

Intel FPGA Avalon® Mailbox (simple) has only one clock domain with one associated reset interface. Requirement of different clock domains between two processors is handled through the Platform Designer fabric. The following table describes the interfaces behavior of the component.

Table 127.  Component Interface Behavior
Interface Port Description Details
Avalon® MM Agent (sender) Avalon® -MM Agent interface for processor of message sender. This interface apply wait request signal for back pressuring the Avalon® -MM Host if Mailbox is already full.
Avalon® MM Agent (receiver) Avalon® -MM Agent interface for processor of message receiver. This interface only has read capability with readWaitTime=1.
Clock Clock input of component. It supports maximum frequency up to 400MHz on Cyclone IV and 600MHz in StratixIV devices.
Reset_n Active LOW reset input/s. Support asynchronous reset assertion. De-assertion of reset has to be synchronized to the input clock.
IRQ_msg Message Pending Interrupt output to processor of message receiver upon message arrival. The signal will remain high until the message is retrieved. Interrupt assertion and deassertion is synchronized to input clock.
IRQ_space Message Space Interrupt output to processor of message sender whenever Mailbox has space for incoming message. The signal will assert high as long as the Mailbox is yet full. Interrupt assertion and deassertion is synchronized to input clock. The connection of this interrupt port to the top level is depends on configuration parameter of MSG_SPACE_NOTIFY.