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

28.13.2.2. Descriptor Processing

The DMA descriptors specify data transfers to be performed. With the Prefetcher core, a descriptor is stored in memory and accessed by the Prefetcher core through its descriptor write and descriptor read Avalon® -MM host. The mSGDMA has an internal FIFO to store descriptors read from memory. This FIFO is located in the dispatcher’s core. The descriptors must be initialized and aligned on a descriptor read/write data width boundary. The Prefetcher core relies on a cleared Owned By Hardware bit to stop processing. When the owned by Hardware bit is 1, the Prefetcher core goes ahead to process the descriptor. When the Owned by Hardware bit is 0, the Prefetcher core does not process the current descriptor and assumes the linked list has ended or the next descriptor linked list is not yet ready.

Each time a descriptor has been processed, the core updates the Actual Byte Transferred, Status and Control fields of the descriptor in memory (descriptor write back). The Owned by Hardware bit in the descriptor control field is cleared by the core during descriptor write back. Refer to software programming model section to know more about recommended way to set up the Prefetcher core, building and updating the descriptor list.

In order for the Prefetcher to know which memory addresses to perform descriptor write back, the next descriptor pointer information will need to be buffered in Prefetcher core. This buffer depth will be similar to descriptor FIFO depth in dispatcher core. This information is taken out from buffer each time a response is received from dispatcher.