Showing posts from July, 2017

Best FPGA development practices - Whitepaper

This whitepaper by Charles Fulk and RC Cofer is an excellent summary of several techniques, tools and design guidelines for FPGA:

FPGA design processRevision controlCoding guidelinesScripting automationPCB design for FPGAVHDL capture and simulation (including OS-VVM package)Project ManagementDesign Resources The whitepaper is available here

Xilinx AXI Stream tutorial - Part 2

Hi again,

On the previous chapter of this tutorial we presented the AXI Streaming interface, its main signals and some of its applications.

Now let's go for the funnier stuff, that is, to actually make and test some VHDL code to implement our AXI master. We will proceed gradually, adding features as we go. At the end of this tutorial you will have code that:
Implements an AXI master with variable packet lengthFlow control support (ready and valid)Option for generation of several kinds of data patternsTestbench to check that all features work OKInclude an instantiation of Xilinx's AXI Stream protocol checker IP to verify the correctness of our AXI master core.

So let's see the first version of an AXI master. In this version we will have fixed data length of the packet, and the data will be a progression of ascending numbers (the same counter that controls that the packet length is reached, is used to generate the packet data):

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Xilinx AXI Stream tutorial - Part 1


In these series of articles I am going to present the design of an AXI4-Stream master. As I often do in my tutorials, I will try to show the design procedure for the block, starting from a "bare bones" solution and gradually adding features to it.

Xilinx provides a wide range of AXI peripherals/IPs from which to choose. My purpose in making my own block was in learning 'hands-on' the protocol. As a side effect, this tutorial provides you with a (synthesizable) AXI4 Stream master which I have not seen provided by Xilinx. The closest IP provided by Xilinx, that I know of, is an AXI memory mapped to AXI stream block.

But first things first, what is AXI4-streaming? Streaming is a way of sending data from one block to another. The idea on streaming devices is to provide a steady flow of high speed data, so usually one new block of data is transferred every clock pulse. Also, to reduce overhead streaming buses do no have addressing. Streaming connections are point to …