Physics 351
Fall 2009

Electronics II
Introduction to Digital Circuits

This course will cover the following digital electronics components and concepts:

     - Binary numbers, logic gates, and Karnaugh maps.
     - Memory, flip-flops, and clocked latches.
     - Clocks, timing, and one-shots.
     - Counters, registers, and state machines.
     - Analog-to-Digital Converters (ADC) and Digital-to-Analog Converters (DAC).
     - Optical and magnetic digital isolation.
     - Field Programmable Gate Arrays (FPGA).
     - Digital Signal Processing (DSP).
     - Surface-mount chips and soldering.

This course has received a QEP-Mellon grant administered by the Charles Center, College of William and Mary. At present, the grant is providing partial support to the course with budget funds for 6-week student research projects. The QEP-Mellon grant has enabled the following key additions to the course over the last three years:

  • FPGAs
         FPGA chips are hardware programmable chips which can be set-up to perform any type of digital operation or series of digital operations (below 100,000 logic gates). A computer is used to program the FPGA so that the thousands of internal circuit components of the FPGA are correctly connected together to form a complete circuit. FPGAs are used to construct complex circuits involving 10,000-100,000 digital circuit elements, including parallel processing circuits. The FPGA programming hard-wires the chip in combination with a flash memory module, so that it does not need to be programmed again (even when the power is turned off). The flexibility and speed of FPGAs have made them the dominant type of all-purpose chip of the digital electronics industry. They are widely used in commercial and research applications, and are currently being integrated into high performance computers and servers as hardware programmable co-processors.
         In physics, FPGAs are used for complex coincidence triggering in particle physics and quantum optics experiments and for high-speed customized control loops in quanum feedback. Physicists are also beginning to use FPGAs for high-speed custom DSP circuits.
  • Circuit Design Software
         The FPGAs will programmed using the Quartus II v7.1 software with GUI circuitry much like 5Spice for analog circuit and with the Verilog FPGA programming language (similar to C) -- see figure below. Quartus II can also be used to design and simulate almost any digital circuit (even those not destined for FPGAs).

         Students are strongly encouraged to download and install Quartus II v7.1 WebEdition onto their personal computers. The software is free, but requires a license which must requested from Altera Inc.

  • FPGA educational development kits
         The course will use the traditional electronics breadboard in combination with the FPGA educational development board shown below.

         Simple circuits will constructed on the breadboard, while more complex ones will implemented in the FPGA. The FPGA board and the breadboard can be connected to make hybrid circuits, such as a digital signal processor (DSP).

  • Research Design Project
         The course will feature a 6 week project in which teams of 2-3 students will design and construct a DSP electronic device based on an FPGA, and useful for physics research. Each team will have a small set of funds to design and construct the device. Students will gain valuable research, design, and construction experience with this project.

Web page updated: August 31, 2009.