Sponsored

Modular FPGA-Based Solution Smooths Development of Instrumentation Designs

Written by Digilent

What’s the best way to simplify the challenge of adding instrumentation-grade analog I/O to your FPGA-based systems? The Eclypse-Z7 platform offers a solution.

The Eclypse Z7 is the first host board of Digilent’s new Eclypse platform, showcasing modular functionality, high-speed I/O, and an FPGA SoC that blends power and flexibility for instrumentation applications. Because we expect the industry trend for more RF communications, test, and software-defined radio (SDR) applications to drive the integration of higher-speed analog into new devices, we wanted to simplify the challenge of adding instrumentation-grade analog I/O to our FPGA-based systems, speeding up the development, research, and prototyping processes. Eclypse is a new way to streamline and accelerate design flow combined with a newly developed software architecture to create a platform optimized for productivity and flexibility.

The Eclypse Z7 FPGA/SoC development board is specifically designed to enable the rapid prototyping and development of embedded measurement systems. Featuring high-speed Zmod ports for modular expansion, a Xilinx Zynq-7020 SoC plus software API from Digilent, the Eclypse Z7 shortens the time it takes for engineers and researchers to develop innovative and powerful new high-speed instrumentation, control, and measurement systems.

A New Standard
In addition to a Zynq 7020 FPGA SoC from Xilinx, the Eclypse Z7 features two high-speed connectors using Opal Kelly’s new SYZYGY standard. Until recently, prototyping or developing new FPGA-based systems has been limited by the capabilities of the two most common expansion schemes. Pmods, created by Digilent and popular on many FPGA development boards, are a common and low-cost option. FPGA Mezzanine Card (FMC or VITA 57.1), is a larger and more expensive option.  SYZYGY fits – in cost, size, and performance – somewhere between the existing Pmod and FMC standards.

Although not much larger than Pmods, SYZYGY-compatible modules are capable of high-bandwidth connections to an FPGA, enabling very compact and cost-effective high performance I/O.  With the new modules we’ve created to be used with SYZYGY, “Zmods”, you will be able to simply plug in an application-specific module that is suited for their prototyping or testing needs, utilize our “Getting Started” demos, and be up and running in hours or days, instead of weeks or months.  We will have two Zmods, the Zmod ADC 1410 and Zmod DAC 1411, both with 100MSPS, 14-bit converters.

Zmods – High Speed Converters
The Zmod DAC and Zmod ADC are intended to be included in user-defined data acquisition or signal processing systems. SYZYGY recommends them for compact, configurable, and rugged systems, though the high bandwidth and sampling rate (100 MSPS), the flexible input/output range, the high resolution, and the flexibility provided by the FPGA interface make them ideal for a wide variety of applications.

A combination of one Zmod DAC and one Zmod ADC together with a SYZYGY-compatible FPGA carrier like Eclypse could be used for closed analog loops with digital control, digital filters with analog input and output, hardware-in-the-loop, digital signal processing, high frequency modulators/demodulators, real time image processing, software-defined radio, etc. One or two Zmods ADCs paired with the Eclypse Z7 could be used to simultaneously digitize two or four analog signals and pass the data to the main system via various interfaces (USB, Ethernet). Two Zmods DACs can generate high sample rate analog signals when used in the same way.

Eclypse Z7 system with case

Software Developers Can Now Communicate with FPGAs
Looking past the hardware components of the Eclypse Platform, a source of value and efficiency will be its software architecture. Traditionally, the languages of software developers and digital designers within a company have been a barrier to communication. It is uncommon to find professionals that are proficient with both C++ and Vivado, for example. However, with Eclypse, there is hope to have less information “lost in translation”.

Users that are unfamiliar with the intricacies and programming of FPGAs will be able to lean on the provided high-level API that allows software languages like C or C++ to interface directly with the FPGA without having to write a single line of hardware description language. As a whole, the platform is completely open and customizable (using Linux to communicate with the pre-constructed IP blocks in the FPGA).  Xilinx’s Petalinux is provided right out of the box, and pre-built Linux images are accompanied by the software API for bulk data transfer.

How Exactly Does It Work?
The Eclypse platform streamlines the entire process:

  1. The user boots their Eclypse Z7 from an SD card containing a system personality that supports their Zmods and then connects their board to a Xilinx SDK workspace containing the software libraries supporting their Zmods.
  2. Then, the user creates (or uses a provided) user-space application for the Eclypse. The application uses the high-level API of the software libraries to configure the Zmod and the hardware present in the Zynq programmable logic and transfer data to and/or from the Zmods.
  3. High-level API function calls are translated into low-level driver calls, which further abstract away AXI communication between the application running in the processing system (PS) and the hardware present in programmable logic (PL). The programmable logic hardware acts as a bridge between the AXI transactions that the processing system uses and the protocol (SPI for the Zmod ADC) that the Zmod’s primary integrated circuit (IC) uses.
  4. Once the Zmod and the PL hardware are both fully initialized, a parallel bus between the PL and the Zmod’s IC becomes ready for use. The high-level API function calls for transferring bulk data are translated into DMA driver function calls, which will do (one or both) of two things: They will take arrays of data from the application, stored in DDR, and send them to buffers in the PL by way of DMA transfers before streaming them out to the Zmod through the SYZYGY interface. Or, they will initiate a DMA transfer to capture the contents of a buffer that data is streaming into from the Zmod, unless trigger conditions are set.
  5. The user then deploys the application to the board, and it executes whatever application that the user designed it to do.

Final Thoughts
What does this all mean? It means that when using the platform, you will have a range of pre-made and customizable options to virtually give you a “plug and play” start for new projects, all but eliminating the need to start from scratch on new designs. 

For more detailed information, specs, and data sheets, visit the online reference manual for the Eclypse Z7 here.

For more information on the specs and features of Zmods, check out their respective reference manuals:

Zmod DAC Reference Page

Zmod ADC Reference Page

Content provided by Digilent Inc.


Don't miss out on upcoming issues of Circuit Cellar. Subscribe today!

 
 
Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.


Would you like to write for Circuit Cellar? We are always accepting articles/posts from the technical community. Get in touch with us and let's discuss your ideas.