Avalon® Interface Specifications

ID 683091
Date 9/26/2022
Document Table of Contents
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B. Document Revision History for the Avalon® Interface Specifications

Document Version Intel® Quartus® Prime Version Changes
2022.09.26 22.3 Added some clarification to the definition of the waitrequestAllowance property in the Interface Properties section.
2022.01.24 20.1 Changed the maximum value of the data signal, the dataBitsPerSymbol parameter, and the symbolsPerBeat parameter to 8192 in the Avalon® Streaming Credit Interface Signal Roles section.
2021.05.27 20.1 Converted non-inclusive terms to "host" and "agent" inclusive terms for Avalon® interface descriptions throughout the document.
2021.04.26 20.1 Added more clarification for the readyLatency property to the Avalon® -ST Interface Properties section. Also added a Note with a description of the Avalon® streaming interconnect that connects Avalon® streaming source/sink BFMs or custom components to the same section.
2020.12.21 20.1 Changed references to readyLatency to the correct parameter readLatency in the Pipelined Read Transfers with Fixed Latency section.
2020.05.26 20.1 Added more description for the timings diagram Figure 27 in section Data Transfers Using readyLatency and readyAllowance .
2020.05.07 20.1

Added some clarification for the timing behavior of the signal writeresponsevalid to the Avalon® Memory-Mapped Interface Signal Roles section.

Updated the bus widths for the data and empty signals in the Avalon® Streaming Interface Signal Roles section.

2020.04.13 20.1 Added the chapter Avalon® Streaming Credit Interfaces.
2020.01.03 18.1 Corrected the definition of the burstOnBurstBoundaries interface property. When true, the burst must begin on a multiple of the maximum burst size.
2019.10.08 18.1

Removed references to symbolsPerBeat because it is a deprecated parameter.

Added a note in the Data Layout topic to clarify that the Avalon Streaming Interface supports both big-endian and little-endian modes.

2019.10.03 18.1 Corrected the property that specifies the fixed latency in the Pipelined Read Transfers with Fixed Latency topic. The readyLatency property, not the readWaitTime property specifies this value.
2018.09.26 18.1 In the Write Bursts section, added a statement saying that writes with byteenables being all 0's are passed on to the Avalon® -MM agent as valid transactions.
2018.09.24 18.1 In Avalon Memory-Mapped Interface Signal Roles, added consecutive byte-enable support.
2018.05.22 18.0 Made the following changes:
  • In the Avalon-ST Interface Properties table, corrected the default value for beatsPerCycle. The default value is 1.
  • In the Avalon-ST Interface Properties table, added legal values for beatsPerCycle. Legal values are 1, 2, 4, and 8.
  • Corrected minor errors and typos.
2018.05.07 18.0 Made the following changes:
  • Added support for the readyAllowance parameter.
  • Updated the Data Transfers with Backpressure topic to incorporate support for the readyAllowance parameter.
  • Fixed minor errors and typos.
2018.03.22 17.1 Made the following changes:
  • Made the following changes to the Read and Write Transfers with Waitrequest timing diagram
    • Removed readdatavalid signal which is not relevant when using waitrequest
    • Moved the number 4, readdata and response forward one cycle.
    • Aligned the read signal to number 1.
  • Expanded the Transfers Using the waitrequestAllowance Property section. Provided more complex timing diagrams.
  • Updated the discussion in the Read Bursts section. For reads with a burstcount > 1, Intel recommends asserting all byteenables.
  • Enhanced discussion in the waitrequestAllowance Equals Two - Not Recommended topic. Corrected timing diagram. Data must be held for 2 cycles starting at clock cycle 11.
November 2017 17.1 Made the following changes:
  • Updated the discussion of Read Bursts as follows:
    • Qualified the statement, " When a host connects directly to a agent, a burstcount of <n>, means the agent must return <n> words of readdata to complete the burst. " This statement is true if the host connects directly to the agent. It may not be true if interconnect links the host and agent.
    • Removed the following statement from the description of read bursts: "The byteenables presented with a read burst command apply to all cycles of the burst." This statement is no longer true. However, Intel recommends that reads with burstcount > 1 assert all byteenables.
  • Removed the following statement form the Pipelined Transfers section: Write transfers cannot be pipelined. You can pipeline writes using the writeresponsevalid signal.
  • Expanded the description of read and write responses in the Avalon® -MM Read and Write Responses Timing Diagram section.
  • Revised the description of the reset_req signal.
  • Changed width of irq from 1 bit to 1-32 bits. Both the Intel® Quartus® Prime Pro Edition and Intel® Quartus® Prime Standard Edition software support interrupt vectors.
May 2017 Quartus® Prime Pro v17.1 Stratix® 10 ES Editions Made the following changes:
  • Added the following interface property parameters.
    • waitrequestAllowance parameter to support high speed operation. This parameter is available for Avalon-MM interfaces. Added timing diagrams illustrating use of this parameter.
    • minimumResponseLatency parameter to facilitate timing closure for Avalon-MM interface. Added timing diagrams illustrating use of this parameter.
December 2015 15.1 Made the following changes:
  • Changed the width of the empty signal from a maximum of 8 bits to a maximum of 5 bits.
  • Improved the definition of the reset_req signal.
  • Removed the readdatavalid signal from the Pipelined Read Transfer with Fixed Latency of Two Cycles timing diagram. This signal is not relevant for fixed latency transfers.
  • Corrected equation defining the empty signal.
  • Made the following changes in the Pipelined Read Transfers with Variable Latency timing diagram:
    • Moved the deassertion of the read signal to cycle 9
    • Changed waitrequest to don't care in cycle 9.
March 2015 14.1 Fixed typo in Figure 1-1.
January 2015 14.1 Made the following changes:
  • Clarified address alignment example. The Avalon-MM host and agent interfaces are different widths.
  • Improved discussion of Pipelined read Transfers with Variable Latency. Corrected timing marker 2 which should be exactly on the rising edge of clock.
  • Improved discussion of Pipelined Read Transfer with Fixed Latency of Two Cycles.
  • Clarified use of beatsPerCycle property.
  • Corrected the address range for line-wrapped bursts. The correct address range for a 64-byte burst is 0x0–0x3C, not 0x0–0x1C.
  • Corrected description of the Tristate Conduit Arbitration Timing diagram in the following ways:
    • The tristate conduit agent asserts grant, not the tristate conduit host.
    • The final grant comes in cycle 9, not cycle 8.
  • Added a Deprecated Signals appendix.
  • Added read response signal.
  • Improved definitions of clock and reset signal types.
  • Corrected definition of clock sink properties.
  • Corrected definition of synchronousEdges for reset source interface.
  • Clarified the Avalon-MM response signal type.
  • Updated definition of empty. The signal must be interpreted emptyWithinPacket is true.
  • Edited for clarity and consistency.
June 2014 14.0
  • Updated the Avalon-MM Signals table, begintransfer, readdatavalid, and readdatavalid_n.
  • Updated the Read and Write Transfers with Waitrequest figure:
    • Moved deassertion of write to cycle 6.
    • Moved assertion of readdatavalid and readdata to cycle 4.
  • Updated the Pipelined Read Transfers with Variable Latency figure:
    • Moved assertion of data1 to just after cycle 5, and assertion of data2 to cycle 6.
    • Moved assertion of readdatavalid to match data1 and data2.
April 2014 13.01 Corrected Read and Write Transfers with Waitrequest In Avalon Memory-Mapped Interfaces chapter .
May 2013 13.0 Made the following changes:
  • Minor updates to Avalon Memory-Mapped Interfaces.
  • Minor updates to Avalon Streaming Interfaces.
  • Updated Avalon Conduit Interfaces to describe the signal roles supported by Avalon conduit interfaces.
  • Updated Shared Pin Types figure in the Avalon Tristate Conduit Interface chapter.
May 2011 11.0 Initial release of the Avalon Interface Specifications.