China
Africa
Explore chapters and articles related to this topic
Introduction
Published in Vlad P. Shmerko, Svetlana N. Yanushkevich, Sergey Edward Lyshevski, Computer Arithmetics for Nanoelectronics, 2018
Vlad P. Shmerko, Svetlana N. Yanushkevich, Sergey Edward Lyshevski
(b)f=x1∨x2x2∨x3x1∨x3. The solution is given in Figure 8.7. Note that this function is called a majority function.
The Exploitation of the Spin-Transfer Torque Effect for CMOS Compatible Beyond Von Neumann Computing
Published in Krzysztof Iniewski, Santosh K. Kurinec, Sumeet Walia, Energy Efficient Computing & Electronics, 2019
Thomas Windbacher, Alexander Makarov, Siegfried Selberherr, Hiwa Mahmoudi, B. Gunnar Malm, Mattias Ekström, Mikael Östling
A further example for the possible application of the flip flop is its use in a nonvolatile buffered gate grid [189], which, like the shift register, takes advantage of passing directly the stored information from one free layer to the next. To create the nonvolatile buffered gate grid, one needs an extra ingredient, the STT majority gate. The majority gate employs the same material stack for the free layer and the polarizers as the flip flop and is also based on the same information encoding principle via input polarity [185,194]. Therefore, the flip flop and the majority gate can be synergetically combined into bigger circuits. Since both devices are similar, the focus will be on explaining the differences between these two and how they interact. First of all the STT majority gate belongs to the class of combinational logic devices, while the flip flop belongs to the class of sequential logic devices. Both types are essential for building a computing environment and complement each other with their functionalities. The most obvious structural difference between them is that the free layer of the STT majority gate is cross shaped and features four instead of three polarizer stacks (cf. Figure 4.17). Three of the polarizer stacks A, B, and C are used as inputs and one polarizer stack Q is used for readout. The STT majority gate is operated via three synchronous polarity encoded input pulses and the final orientation of the free layer is defined by the majority of the input signals. One must mention that it is crucial that the number of applied inputs is odd. Otherwise, it can happen that the number of “0” and “1” input signals are equal, and the created torques perfectly balance each other (assuming equal input currents and equal torque strength), which leads to an undefined state after the operation. Only when an odd number of inputs is applied, there is one uncompensated torque during operation left, which will decide the final state. Another important feature for building arbitrary logic functions is functional completeness. In CMOS logic circuits, the NAND and NOR gates are widely employed due to their functional completeness. Looking at the truth table of the majority function shows that it consists of a two-input AND and a two-input OR gate, when one of the inputs is fixed to logic “0” and “1,” respectively. Therefore, the NOT operation must be added in order to reach functional completeness. The easiest way to introduce the NOT operation is to invert the acting torque by inverting the polarity of the input signal.
A CNFET-based hybrid multi-threshold 1-bit full adder design for energy efficient low power applications
Published in International Journal of Electronics, 2018
Mojtaba Maleknejad, Somayyeh Mohammadi, Keivan Navi, Hamid Reza Naji, Mehdi Hosseinzadeh
Generally, the NAND and NOR functions are a special case of a Majority function or threshold function. A k-out-of-n Majority function (Majorityk (A1,…,An)) gives logic ‘1’ as an output when ‘k’ or more of n inputs are ‘1’, where . The functionality of a Majorityk (a1,…,an) function can be represented with the general threshold equation (6) (Maleknejad et al., 2013).