• Demonstration AXI4-lite slave

• Demonstration APB slave

• Demonstration AXI4(Full) slave -- AXI Addr is a helper core used for calculating the "next" address in a burst sequence. It's based upon the algorithm discussed here.

• A simplified AXI-lite slave

• A basic AXI-lite GPIO controller

• Skidbuffer

• AXIS Broadcast: Accepts one stream input, duplicates that stream to an arbitrary number of output streams
• AXISPACKER: Removes NULL bytes from an AXI Stream
• AXISRANDOM: Generates a pseudorandom AXI-Stream output
• AXISSWITCH: Switches a stream from among many input streams, with an AXI-lite control input for switching between them.

See this post for a discussion of these crossbars.

• AXI4
• AXI4-Lite
• Wishbone

These cores rely not only on the skidbuffer listed above, but also upon a separate address decoder that is common to all of them.

All three cores are supported by the (dev branch of) AutoFPGA.

• AXIMM2S. Supports unaligned transfers, but only fully aligned stream words.

• AXIS2MM. Doesn't yet support unaligned transfers. It may eventually, but it will also only ever support full word transfers through the stream.

• AXIDMA. Supports unaligned transfers.

• AXISGDMA. A scatter-gather DMA implementation. Performs DMA operations based upon an external, bus-fetched, table containing the details of multiple DMA operations to be done. -- AXILFETCH--A ZipCPU instruction fetch module required by the Scatter-Gather engine to fetch tables from memory. -- AXISGFSM--The FSM that reads instructions (i.e. table entries) from the fetch routine, and issues instructions to the AXIDMA.

• AXIVFIFO. A virtual FIFO, using an external AXI device for memory backing--perhaps even an SDRAM. It doesn't really matter--it just needs to be AXI.

• AXIVCAMERA. Writes a video stream to a memory frame buffer.

• AXIVDISPLAY. Reads a frame buffer from memory to generate a continuous AXI-stream video source output.

• Synchronous FIFO

• Synchronous FIFO with threshold

• AXI to AXI-lite. Supports 100% throughput even across burst boundaries, unlike other (similar) bridges of this type you might come across.

• AXI-lite to AXI. A "no-cost" bridge.

• AXI-lite to AXI stream

• AXI-Lite to Wishbone

  -- Read side

  -- Write side

  -- A following (optional) arbiter will connect read and write sides together into the same WB bus. Alternatively, each of the two sides can be submitted separately into a WB Crossbar.

• AXI-Lite to APB

• AXI4 Master to Wishbone

  -- Read side

  -- AXI4 Master to Wishbone

• Wishbone classic to pipelined

• Wishbone pipelined to classic

• Wishbone master to AXI4-Litejk slave

• Wishbone master to AXI4 slave

  This core, together with its sister core, migsdram, form the basis for my approach to accessing DDR3 SDRAM memory through an AXI interface using Xilinx's MIG controller. Other than the lag in going through the bridge, this solution works quite well--achieving full (nearly 100%) bus throughput when loaded.

• AXI3 to AXI4. See the internal documentation of the AXI3 write deinterleaver for the details of the write deinterleaving algorithm.

• The AXI4 to AXI3 bridge is still missing. This will be more difficult than its AXI3 to AXI4 sister above, since it will need to break apart large AXI4 burst requests into smaller AXI3 bursts, sort of like the AXI4 to AXI4-lite bridge does.

These follow from the discussion in this article about how to simplify a bus interconnect into something allowing easier integration of multiple slaves into a design. They work by aggregating the signaling logic across many slaves together. See the headers for each of the cores for the specifics of the standard subsets they support.

• AXI Single, the companion to the AXI Double core has not yet been written. The design for it should be nearly identical. The big difference between single and double AXI slaves is that single slaves can have only one address, and that address must always be available for reading.

• AXI Double.

• AXI-Lite Single

• AXI-Lite Double

The goal of these firewall(s) is to create a core that, when placed between the bus master and slave, will guarantee that the slave responds appropriately to the bus master---even in the presence of a broken slave. If the slave is broken, the firewall will raise a flag that can then be used to trigger a logic analyzer of some type so you can dig deeper into what's going on.

As a bonus, the firewall may also have the capability of resetting the downstream core upon any error, so that it might be reintegrated later into the rest of the design for additional testing.

• AXI-lite

• AXI4

• AXI-stream

• Wishbone

• AXIPERF -- Useful for measuring Latency and Throughput in an AXI bus. Has an AXI-lite interface, and an AXI4 monitor interface. Monitors the AXI4 bus, and measures key performance statistics. Statistics may be read and cleared via the AXI-lite interface.

These are used to simplify interconnect generation. When there are no slaves connected to an interconnect, the interconnect generator can automatically connect one of these slaves (depending on the protocol) and be guaranteed that the protocol will still be followed. All requests, however, will return bus errors.

• AXIEMPTY - the AXI4 empty slave

• AXILEMPTY - the AXI4-lite empty slave

• Wishbone cross-clock domains

• AXI4 cross-clock domains

• APB cross-clock domains

• Asynchronous FIFO -- support function