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

15.2.4. Read Operation

The Avalon® read data width is 32 bits wide. A 32-bit width limits the bridge to only issue word align Avalon® addresses. It also allows the upstream I2C host to read any sequence of bytes on any address alignment. The conversion logic which sits between the Avalon® interface and I2C interface, translates the address alignment and returns the correct 8-bit data to the I2C host from the 32-bit Avalon® read data.

Read Operation conversion logic flow:

  • Checks the address alignment issued by the I2C host (first byte, second byte, third byte or forth byte).
  • Issues a word align Avalon® address according to the address sent by the I2C host with the two LSBs zero.
  • Returns read data to the I2C host according to the address alignment.

This IP supports three types of read operations:

  • Random address read
  • Current address read
  • Sequential read

Upon receiving of the agent address with the R/W bit set to one, the bridge issues an acknowledge to the I2C host. The bridge keeps the Avalon® read signal high for one clock cycle with the Avalon® wait request signal low, then receives an 8-bit Avalon® read data word and upstreams the read data to the I2C host.