Intan Technologies, LLC: low-noise amplifier microchips for electrophysiology, EKG, EMG, EEG, ECoG, and neural recording headstages and bio instrumentation

Opal Kelly XEM6010

Opal Kelly XEM6010 module used for the Rhythm interface. This device, along with the Rhythm Verilog/C++ code supplied by Intan Technologies, allows multiple RHD2000 chips to be controlled and sampled in real time by a host computer.


RHD2000 Rhythm v1.5 USB/FPGA interface datasheet (updated 3 May 2016)

Release notes for Rhythm v1.5.1 (29 March 2017)

Download complete Rhythm v1.5.1 C++ API source code (including pre-compiled FPGA configuration file)

Download Rhythm v1.5 FPGA Verilog HDL source code (no changes from v1.4; only required if you wish to modify the FPGA configuration; requires Xilinx WebPack)

Opal Kelly XEM6010 module


RHD2000 series chip datasheet

RHD2000 web page

RHD2000 USB/FPGA interface: Rhythm


To facilitate the development of electrophysiology recording systems using the revolutionary RHD2000 series of microchips, Intan Technologies provides the following open-source USB/FPGA interface for developers.  Designated Rhythm, the interface consists of Verilog HDL code and a C++ API written for the commercially-available Opal Kelly XEM6010 USB/FPGA interface module.  Rhythm configures the Xilinx FPGA (field programmable gate array) on the Opal Kelly module to communicate with up to eight RHD2000 chips over LVDS SPI buses and to stream data from these chips to a host computer over a high-speed USB 2.0 interface.

The Rhythm software interface is designed for multi-platform development under Windows, Mac, or Linux.  All API software is written in C++ to facilitate rapid development.  This datasheet provides documentation on the Rhythm hardware and software protocols so that developers may quickly link the RHD2000 chips to a host computer of their choice.

Rhythm supports real-time streaming of up to 256 amplifier channels from multiple RHD2000 chips, auxiliary data from the chips (e.g., special chip functions such as temperature sensing), data from up to eight other ADCs, and signals from 16 digital inputs.  All data is synchronized and time-stamped before transmission over a standard USB 2.0 bus to the host computer.

The host computer may configure the Rhythm-based module to set the RHD2000 per-channel sampling rate between 1 kS/s and 30 kS/s for a wide variety of electrophysiology recording applications (e.g., neural spikes, EMG, EKG).  Custom RHD2000 command sequences may be uploaded to the FPGA for transmission over the SPI buses.  Selected amplifier channels may be directly routed to eight optional DACs for analog signal reconstruction or audio monitoring with minimal latency.

The Rhythm interface is used at the core of the RHD2000 Evaluation System, which offers a quick way to evaluate the performance and operation of RHD2000 chips with a plug-and-play USB interface and open-source multi-platform GUI software written in C++/Qt.

Rhythm Interface Features

  • Open-source Verilog hardware description language (HDL) code configures a Xilinx field-programmable gate array (FPGA) to communicate with multiple RHD2000 digital electrophysiology chips
  • Verilog code is written for a commercially-available Opal Kelly XEM6010 module with integrated high-speed USB 2.0 interface
  • Up to 256 simultaneous amplifier channels supported at sample rates up to 30 kS/s per channel
  • Programmable FPGA clock for RHD2000 interface: sample rates from 1 kS/s to 30 kS/s per channel supported
  • Open-source host computer application programming interface (API) in C++ for multi-platform support
  • Module can interface with eight 16-bit digital-to-analog converters (DACs) and route selected amplifier channels to selected DACs for analog signal reconstruction or audio monitoring with minimal latency (< 200 microseconds)
  • Low-latency digital comparators with optional high-pass filters for real-time neural spike detection
  • Optional control of eight 16-bit analog-to-digital converters (ADCs) for auxiliary analog inputs synchronized to all RHD2000 amplifier channels
  • Auxiliary digital I/O: 16 digital input lines and 16 digital output lines supported

Rhythm Interface Applications

  • Windows, Mac, or Linux-based electrophysiology signal acquisition systems
  • Rapid prototyping of Intan Technologies RHD2000-based products
  • Starting point for the development of custom interfaces to RHD2000 chips
© 2010-2017 Intan Technologies, LLC. All Rights Reserved