Embedded Peripherals IP User Guide

ID 683130
Date 9/18/2024
Public
Document Table of Contents
1. Introduction 2. Avalon® -ST Multi-Channel Shared Memory FIFO Core 3. Avalon® -ST Single-Clock and Dual-Clock FIFO Cores 4. Avalon® -ST Serial Peripheral Interface Core 5. SPI Core 6. SPI Agent/JTAG to Avalon® Host Bridge Cores 7. Intel eSPI Agent Core 8. eSPI to LPC Bridge Core 9. Ethernet MDIO Core 10. Intel FPGA 16550 Compatible UART Core 11. UART Core 12. JTAG UART Core 13. Intel FPGA Avalon® Mailbox Core 14. Intel FPGA Avalon® Mutex Core 15. Intel FPGA Avalon® I2C (Host) Core 16. Intel FPGA I2C Agent to Avalon® -MM Host Bridge Core 17. Intel FPGA Avalon® Compact Flash Core 18. EPCS/EPCQA Serial Flash Controller Core 19. Intel FPGA Serial Flash Controller Core 20. Intel FPGA Serial Flash Controller II Core 21. Intel FPGA Generic QUAD SPI Controller Core 22. Intel FPGA Generic QUAD SPI Controller II Core 23. Interval Timer Core 24. Intel FPGA Avalon FIFO Memory Core 25. On-Chip Memory (RAM and ROM) Intel FPGA IP 26. On-Chip Memory II (RAM or ROM) Intel FPGA IP 27. Optrex 16207 LCD Controller Core 28. PIO Core 29. PLL Cores 30. DMA Controller Core 31. Modular Scatter-Gather DMA Core 32. Scatter-Gather DMA Controller Core 33. SDRAM Controller Core 34. Tri-State SDRAM Core 35. Video Sync Generator and Pixel Converter Cores 36. Intel FPGA Interrupt Latency Counter Core 37. Performance Counter Unit Core 38. Vectored Interrupt Controller Core 39. Avalon® -ST Data Pattern Generator and Checker Cores 40. Avalon® -ST Test Pattern Generator and Checker Cores 41. System ID Peripheral Core 42. Avalon® Packets to Transactions Converter Core 43. Avalon® -ST Multiplexer and Demultiplexer Cores 44. Avalon® -ST Bytes to Packets and Packets to Bytes Converter Cores 45. Avalon® -ST Delay Core 46. Avalon® -ST Round Robin Scheduler Core 47. Avalon® -ST Splitter Core 48. Avalon® -MM DDR Memory Half Rate Bridge Core 49. Intel FPGA GMII to RGMII Converter Core 50. HPS GMII to RGMII Adapter Intel® FPGA IP 51. Intel FPGA MII to RMII Converter Core 52. HPS GMII to TSE 1000BASE-X/SGMII PCS Bridge Core Intel® FPGA IP 53. Intel FPGA HPS EMAC to Multi-rate PHY GMII Adapter Core 54. Intel FPGA MSI to GIC Generator Core 55. Cache Coherency Translator Intel® FPGA IP 56. Lightweight UART Core

13.2. Functional Description

Intel FPGA Avalon® Mailbox provides two 32-bit registers for message passing between processors, Command register (0x0) and Pointer register (0x1). The message sender processor and message receiver processor have individual Avalon® Memory Mapped ( Avalon® -MM) interfaces to a Mailbox component. A write to the command register by the sender processor indicates a pending message in the Mailbox and an interrupt will be issued to the receiver processor. Upon retrieval of the message by the receiver processor via a read transaction, the message is consumed, Mailbox is empty. The status register (0x2) is used to indicate if the Mailbox is full or empty.

The Mailbox Avalon® -MM interface which receives messages, or identified as sender interface, will back pressure the sender if there is message pending in the Mailbox. This will ensure every single message passed into the Mailbox is not overwritten. Upon message arrival, the receiving processor will then receive a level interrupt by the Mailbox. The interrupt will hold high until the single message is retrieved from the Mailbox via the Avalon® -MM interface of receiving processor.

In addition, the Interrupt Masking Register (0x3) is writable by the Avalon® -MM interface to mask its dedicated interrupt output. For example, receiver interface will be able to set the mask bit to mask off the message pending interrupt generated by Mailbox. Meanwhile, sender interface will be able to set the mask bit to mask off the message space interrupt output.

Figure 43.  Intel FPGA Avalon® Mailbox (simple) Block Diagram

The Mailbox is clocked with single source. Both of the Avalon® -MM Agent interfaces have its individual function to set and clear the Full bit and Message Pending bit. The Avalon® -MM Agent of the sender processor will only set the status bits, while the Avalon® -MM Agent of the receiver processor only clears the status bit.

An interrupt is derived from the Status register bits. It will remain high until the message in the Mailbox is read.