X P L A N AT I O N : F P G A 1 0 1
This is the third in a planned series of hands-on Zynq-7000 All Programmable SoC tutorials by Adam Taylor. Earlier installments appeared in Xcell Journal issues 82 and 83. A frequent contributor to Xcell Journal, Adam is also a blogger at All Programmable Planet (www.programmableplanet.com).
ne of the real advantages of the Xilinx® Zynq™7000 All Programmable SoC is the ability to increase the performance of the processing system (PS) side of the device by creating a peripheral within the programmable logic (PL) side. At first you might think this would be a complicated job. However, it is surprisingly simple to create your own peripheral. Adding a peripheral within the PL can be of great help when you’re trying to speed up the performance of your processing system or when you’re using the PS to control the behavior of the design within the programmable logic side. For example, the PS might use a number of memory-mapped registers to control operations or options for the design within the programmable logic. Our example design is a simple module that allows you to turn on and off a memory-mapped LED on the ZedBoard. To create this module, we will use the Xilinx PlanAhead™, XPS and Software Development Kit (SDK) tool flow in a three-step process.
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1. Create the module within the Embedded Development Kit (EDK) environment. 2. Write the actual VHDL for our module and build the system. 3. Write the software that uses our new custom module. CREATING THE MODULE IN EDK To create your own peripheral, you will first need to open Xilinx Platform Studio (XPS) from the PlanAhead project containing your Zynq SoC design and select the menu option “hardware->create or import peripheral.” For our example module, the seven LEDs on the ZedBoard should demonstrate a walking display, illuminating one after the other, except that the most significant LED will be toggled under control of the software application. While this is not the most exciting application of a custom block, it is a useful simple example to demonstrate the flow required. Once you’ve grasped that process, you will know everything you need to know to implement more-complex modules. Third Quarter 2013
Xcell Journal
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