Modular FPGA-Based Solution Smooths Development of Instrumentation Designs

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.

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.

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.