The XEM7305 is a compact FPGA board featuring the Xilinx Spartan-7 FPGA and SuperSpeed USB 3.0 connectivity via a USB 3.0 Type C receptacle.

Designed as a development board and full-featured integration module, the XEM7305 provides access to up to 108 I/O pins on its 324-pin Spartan-7 device and has a 512-MiByte DDR3 SDRAM available to the FPGA. One SPI Flash device provides a total of 32 MiB of non-volatile memory (System Flash) which holds the device firmware and can be used to store FPGA configuration bitfiles.

The XEM7305 is designed for compact system integrations in applications where the peripheral can provide the necessary power supplies to the module.

Documentation and Reference Materials

The following is a comprehensive list of documentation available for this device.

XEM7305 User’s ManualThis online documentation space.
XEM7305 Pins ReferenceThe interactive Pins reference for the device provides detailed pinout
information as well as automated constraint file generation. Export
functionality is provided to PDF, CSV. Constraint files are provided
for UCF, XCD (Xilinx) and QSF, SDF (Altera).
FrontPanel SDK User’s ManualThe online documentation space for the FrontPanel SDK.
FrontPanel API ReferenceOnline API reference with detailed usage for every API method.

Functional Block Diagram


The XEM7305 is built around the Xilinx Spartan-7 XC7S50-1CSGA324C. The device has the following resources as derived from the Xilinx documentation.

Logic Elements (LE)52,160
Max Distributed RAM600 Kb
Block RAM2,700 Kib
25×18 Multipliers120

SuperSpeed USB 3.0 Interface

The XEM7305 uses a Cypress FX3 USB microcontroller to make the device a high-performance SuperSpeed USB 3.0 peripheral. As a USB peripheral, the device is instantly recognized as a plug and play peripheral on millions of PCs. More importantly, FPGA downloads to the XEM happen quickly, virtual instruments under FrontPanel update quickly, and data transfers are blazingly fast.

On-board Peripherals

The XEM7305 is designed to compactly support a large number of applications with a small number of on-board peripherals.  These peripherals are listed below.

Low-Jitter Crystal Oscillator

A fixed-frequency, 200 MHz, low-jitter oscillator is included on-board and outputs LVDS to the FPGA. The Spartan-7 FPGA can produce a wide range of clock frequencies using the on-chip PLL capabilities.

512-MiByte Word-Wide DDR3 Synchronous DRAM

The module also includes a 512-MiByte DDR3 SDRAM with a full 16-bit word-wide interface to the FPGA.  This SDRAM is attached exclusively to the FPGA and does not share any pins with the expansion connector. The maximum clock rate supported by the Spartan 7 is DDR3-650 (325 MHz).

The DDR3 SDRAM is a Micron MT41K256M16HA-125:E (or compatible).

System Flash – 16 MiB Serial Flash Memory

A 128 Mib serial flash device (Micron N25Q128A13B1240E or equivalent) provides on-board non-volatile storage accessible to the USB microcontroller.  This device is used to store device firmware and configuration settings as well as other user assets such as FPGA configuration files or calibration data.  Erase, read, and write functions are available at all times (with or without a configured FPGA) through the use of FrontPanel API methods. This device is not directly accessible to the FPGA.


Four LEDs and are available for general use as indicators.

FrontPanel Support

The XEM7305 is fully supported by Opal Kelly’s FrontPanel Application.  FrontPanel augments the limited peripheral support with a host of PC-based virtual instruments such as LEDs, hex displays, pushbuttons, toggle buttons, and so on.  Essentially, this makes your PC a reconfigurable I/O board and adds tremendous value to the XEM7305 as an experimentation or prototyping system.

Programmer’s Interface

In addition to complete support within FrontPanel, the XEM7305 is also fully supported by the FrontPanel SDK, a powerful C++ class library available to Windows, Mac OS X, and Linux programmers allowing you to easily interface your own software to the XEM.

In addition to the C++ library, wrappers have been written for C#, Java, and Python making the API available under those languages as well. Sample wrappers (unsupported) are also provided for Matlab and LabVIEW.

Complete documentation and several sample programs are installed with FrontPanel.


Software, documentation, samples, and related materials are Copyright © 2006-2021 Opal Kelly Incorporated.

Opal Kelly Incorporated
Portland, OR 

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