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

4.2.4.1. Host Mode Operation

In host mode, the SPI ports behave as shown in the table below.

Table 8.  Host Mode Port Configurations
Name Direction Description
mosi output Data output to agent(s)
miso input Data input from agent(s)
sclk output Synchronization clock to all agents
ss_nM output Agent select signal to agent M, where M is a number between 0 and 31.

In host mode, an intelligent host (for example, a microprocessor) configures the SPI core using the control and slaveselect registers, and then writes data to the txdata buffer to initiate a transaction. A host peripheral can monitor the status of the transaction by reading the status register. A host peripheral can enable interrupts to notify the host whenever new data is received (for example, a transfer has completed), or whenever the transmit buffer is ready for new data.

The SPI protocol is full duplex, so for every transaction both sends and receives data at the same time. The host transmits a new data bit on the mosi output and the agent drives a new data bit on the miso input for each active edge of sclk. The SPI core divides the Avalon® memory-mapped interface system clock using a clock divider to generate the sclk signal.

When the SPI core is configured to interface with multiple agents, the core has one ss_n signal for each agent. During a transfer, the host asserts ss_n to each agent specified in the slaveselect register. Note that there can be no more than one agent transmitting data during any particular transfer, or else there will be a contention on the miso input. The number of agent devices is specified at system generation time.