Embedded Peripherals IP User Guide

ID 683130
Date 8/11/2025
Public
Document Table of Contents
1. Introduction 2. Avalon® -ST Single-Clock and Dual-Clock FIFO Cores 3. Avalon® -ST Serial Peripheral Interface Core 4. SPI Core 5. SPI Agent/JTAG to Avalon® Host Bridge Cores 6. Intel eSPI Agent Core 7. eSPI to LPC Bridge Core 8. Ethernet MDIO Core 9. Intel FPGA 16550 Compatible UART Core 10. 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. Intel FPGA Avalon® Compact Flash Core 17. EPCS/EPCQA Serial Flash Controller Core 18. Intel FPGA Serial Flash Controller Core 19. Intel FPGA Serial Flash Controller II Core 20. Intel FPGA Generic QUAD SPI Controller Core 21. Intel FPGA Generic QUAD SPI Controller II Core 22. Interval Timer Core 23. Intel FPGA Avalon FIFO Memory Core 24. On-Chip Memory (RAM and ROM) Intel FPGA IP 25. On-Chip Memory II (RAM or ROM) Intel FPGA IP 26. Optrex 16207 LCD Controller Core 27. PIO Core 28. PLL Cores 29. DMA Controller Core 30. Modular Scatter-Gather DMA Core 31. Scatter-Gather DMA Controller Core 32. SDRAM Controller Core 33. Tri-State SDRAM Core 34. Video Sync Generator and Pixel Converter Cores 35. Intel FPGA Interrupt Latency Counter Core 36. Performance Counter Unit Core 37. Vectored Interrupt Controller Core 38. Avalon® -ST Data Pattern Generator and Checker Cores 39. Avalon® -ST Test Pattern Generator and Checker Cores 40. System ID Peripheral Core 41. Avalon® Packets to Transactions Converter Core 42. Avalon® -ST Multiplexer and Demultiplexer Cores 43. Avalon® -ST Bytes to Packets and Packets to Bytes Converter IP 44. Avalon® -ST Delay Core 45. Avalon® -ST Round Robin Scheduler Core 46. Avalon® -ST Splitter Core 47. Avalon® -MM DDR Memory Half Rate Bridge Core 48. Intel FPGA GMII to RGMII Converter Core 49. HPS GMII to RGMII Adapter Intel® FPGA IP 50. Intel FPGA MII to RMII Converter Core 51. HPS GMII to TSE 1000BASE-X/SGMII PCS Bridge Core Intel® FPGA IP 52. Intel FPGA HPS EMAC to Multi-rate PHY GMII Adapter Core 53. Intel FPGA MSI to GIC Generator Core 54. Cache Coherency Translator Intel® FPGA IP 55. Altera ACE5-Lite Cache Coherency Translator 56. Lightweight UART Core

45.3.2. Operations

If a particular channel is almost full, the Avalon® -ST Round Robin Scheduler will not schedule data to be read from that channel in the source component.

The Avalon® -ST Round Robin Scheduler only requests 1 beat of data from a channel at each transaction. To request 1 beat of data from channel n, the scheduler writes the value 1 to address (4 ×n). For example, if the scheduler is requesting data from channel 3, the scheduler writes 1 to address 0xC.

At every clock cycle, the Avalon® -ST Round Robin Scheduler requests data from the next channel. Therefore, if the Avalon® -ST Round Robin Scheduler starts requesting from channel 1, at the next clock cycle, it requests from channel 2. The Avalon® -ST Round Robin Scheduler does not request data from a particular channel if the almost-full status for the channel is asserted. In this case, one clock cycle is used without a request transaction.

The Avalon® -ST Round Robin Scheduler cannot determine if the requested component is able to service the request transaction. The component asserts waitrequest when it cannot accept new requests.

Table 451.  Ports for the Avalon® -ST Round Robin Scheduler
Signal Direction Description
Clock and Reset
clk In Clock reference.
reset_n In Asynchronous active low reset.
Avalon® -MM Request Interface
request_address (log 2 Max_Channels–1:0) Out The write address used to signal the channel the request is for.
request_write Out Write enable signal.
request_writedata Out The amount of data requested from the particular channel.

This value is always fixed at 1.

request_waitrequest In Wait request signal, used to pause the scheduler when the agent cannot accept a new request.
Avalon® -ST Almost-Full Status Interface
almost_full_valid In Indicates that almost_full_channel and almost_full_data are valid.
almost_full_channel (Channel_Width–1:0) In Indicates the channel for the current status indication.
almost_full_data (log 2 Max_Channels–1:0) In A 1-bit signal that is asserted high to indicate that the channel indicated by almost_full_channel is almost full.