Digital Design on FPGA using XILINX

A two-day workshop conducted by Chitkara University Himachal Pradesh for third year ECE students during March 17-18, 2016

FPGA stands for Field Programmable Gate Array; it is a semiconductor technology that let designer customize/configure the semiconductor IC after manufacturing at hardware level, hence it is called "Field Programmable". This configuration is done through Hardware Description Language (HDL). Recently our students were exposed to FPGA design where they had simulated and synthesized combinational & sequential circuits using Xilinx ISE Webpack Design Software and implemented it on Nexys 4 trainer board featuring Artix-7 FPGA from Xilinx.

Students understanding the FPGA Architecture

What is FPGA architecture and how it is different and useful when compared to ASIC (Application Specific Integrated Circuits) is discussed in this article.

At a very high level of abstraction, FPGA is regarded as a configurable silicon chip which consists of large number of logic blocks called CLBs (configurable logic blocks) and Programmable Interconnects. Then there are some other specific logic blocks like Block RAM and CLOCK (PLL, DLL) etc. All these blocks and interconnects can be programmed using HDL to perform any specific task. You can for example implement a simple AND logic on a FPGA chip and design a complex microcontroller on a same FPGA chip.

FPGA Architecture

We have another set of semiconductor ICs called ASIC (Application Specific Integrated Circuits) these are semiconductor ICs that are designed to perform any specific task for example 2X1 MUX IC, 8 to 3 encoder ICs is ASIC. Similarly microcontroller that we use has fixed memory, fixed number of I/O ports, fixed clock speed, fixed size of resistors etc is an ASIC where we cannot change anything. But in FPGA you can design a microcontroller that has any number of IO ports, any amount of memory you desire, any clock speed you want and any registers size you need. The only limiting factor is number of logic blocks available in a particular FPGA chip. You can use same FPGA to implement 2X1 MUX and 8 to 3 encoder! There are large number of design suites like XILINX ISE available today that let you write C codes or draw graphical blog diagrams which can be converted into digital circuitry on FPGA chip hence designer need not know the complete hardware design in depth. The biggest advantage with FPGA over ASIC is that FPGA is more cost efficient (as NRE cost in ASIC could be in million or dollars) and it greatly reduce the time to market.

In the two day workshop on "Digital Design on FPGA using XILINX" organized by ECE department of Chitkara University Himachal Pradesh in collaboration with CSI & IETE Students' Chapter during March 17-18, 2016, students learned the FPGA design flow; they were given an overview of XILINX ISE design suit; they designed, simulated and synthesized combinational logic circuits on XILINX ISE and implemented them on Nexys 4 trainer board. They were also exposed to Verilog on XILINX ISE.

There were about 50 students of ECE third year attended the workshop. Thanks are due to Dr. Rajnish Sharma – Dean Academics, Chitkara University Himachal Pradesh for organizing this workshop and Pine Training Academy Ghaziabad for their technical expertise.

By Sagar Juneja, Research Associate, Chitkara University