Designing Asynchronous Circuits Using Null Convention Logic Ncl PDF Download

"This Master's thesis outlines the design of a completely asynchronous Field Programmable Gate Array (FPGA) for implementing NULL Convention Logic (NCL) digital circuits. The proposed design uses four Configurable Logic Blocks (CLB), each of which in turn is designed using four Logic Elements (LE) to implement NCL logic function. Each LE can be configured to function as any one of the 27 fundamental NCL gates. A Logic Element is designed by concatenating a Look-Up-Table (LUT) with a pull-up pull-down transistor chain and a hysteresis loop. The interconnections and the switch box are designed using pass transistors and SRAM. In this thesis, a 4-input Look-Up Table (LUT) based 16-gate FPGA specifically for NCL circuits was designed and successfully programmed as a dual-rail non-pipelined 4-bit NCL register. The design was first created using the schematic capture, followed by layout or the physical level designs subsequent to successful simulation. The NCL FPGA is simulated at the transistor level using the 1.8V, 180nm TSMC CMOS process. The size of FPGAs is now more than 1 million equivalent gates, making them a viable alternative to custom design for all but the most complex processors. FPGAs are relatively low-cost and are reconfigurable, making them perfect for prototyping, as well as implementing the final design, especially for low volume production. To compete with this cheap, reconfigurable synchronous implementation, an NCL-specific FPGA is needed, such that NCL circuits can be implemented without necessitating a prohibitively expensive full-custom design"--Abstract, leaf iii.