Nor gate cmos design software

As with the nor gate, the pmos are 202 and the nmos are 102. Cmos technology and logic gates mit opencourseware. Tutorial 1 vlsi electric nandnor layout design abd almonam zahed. Lab6 designing nand, nor, and xor gates for use to design. Commercial fpga asic design software using verilog or vhdl, can take a design description stated in and or not, and translate that into whatever form the real implementation technology needs. Digital logic and gate digital gates electrical technology. National central university ee6 vlsi design 5 logic gate design nand gate rp the effective resistance of pdevice in a minimumsized inverter n width multiplier for pdevices in this gate k the fanout m fanin of gate cg gate capacitance of a minimumsized inverter cd sourcedrain capacitance of a. Rulesfordesigningcomplementarycmosgates digitalcmos. This is the first of five labs in which you will use the electric vlsi design system to design the bit mips 8 microprocessor described in the cmos vlsi design book. Someone please explain to me how the circuit below operates as nor gate. Not surprisingly, the answers to this question reveal a simplicity of design much like that of the cmos inverter over its ttl equivalent.

Static logic design of nand, nor, xor and xnor gates. Lab 6 design, layout, and simulation of cmos nandnor. Cd4001b, cd4002b, and cd4025b nor gates provide the system designer with direct implementation of the nor function and supplement the existing family of cmos gates. Design of nand gate in microwind mumbai university. The layout of the circuit includes the vdd and ground lines. Two nchannel mosfets and two complementary pchannel mosfets form a twoinput cmos nor logic gate. What is the best software to simulate cmos transistors in a logic. Fortunately, there is an easy solution to this dilemma, one that is used frequently in cmos logic circuitry. A cmos nor gate circuit uses four mosfets just like the nand gate, except that its transistors are differently arranged. Jul 09, 2015 nor logic gate is called as the universal logic gate. In case of nand gate, 3 pmos will be connected in parallel and 3 nmos will be connected in series, and other way around in case of 3 input nor gate.

Pdf layout design implementation of nor gate ijeee apm. Lets see how we can design other gates by using nor gate. The nor gate is a digital logic gate that implements logical nor it behaves according to the truth table to the right. As mentioned earlier that cmos complementary metal oxide semiconductor technologies are used to design nor gate. The twoinput nor2 gate shown on the left is built from four transistors. This gate can function as any of the basic logic gates by just making some changes at its input side. This video tutorial help you to design cmos nor gate design using microwind. You can study the timing by applying the right clock signals on the logic gate. I have created a truth table next the diagram based on my understanding of basic mosfet switching.

There are numerous circuit styles to implement a given logic function. There are several ways in which one can design a xor gate using mosfet. This is just a tutorial video and the software used is an open source. We will begin with a nand gate, followed by nor and xor. Aug 04, 2015 nand and nor gate using cmos technology by sidhartha august 4, 2015 12 comments for the design of any circuit with the cmos technology. Cmos nor gate layout design using microwind youtube. Cmos inverter schematic using electric vlsi software for. A sample assignment done on the cmos designing by experts. One of the most popular ic for nor gate is 4025 triple 3input nor gates. Nor is the result of the negation of the or operator. The aim of this experiment is to design and plot the dynamic characteristics of 2input nand, nor, xor and xnor gates based on cmos static logic introduction. A power efficient circuit topology is proposed to implement a lowvoltage cmos 2input passtransistor xor gate.

Which gate is normally preferred while implementing circuits. Lab6 designing nand, nor, and xor gates for use to. What is the best software to simulate cmos transistors in a logic circuit. Design, layout, and simulations of cmos nand, nor, xor gates and a fulladder. Of course, a separate pullup or pulldown resistor will be required for each gate input. From the table it is observed that the output function f is high only when all the inputs a and b are low. Here, pchannel mosfets q 1 and q 2 are connected in series and nchannel mosfets q 3 and q 4 are connected in parallel. The standard, 4000 series, cmos ic is the 4001, which includes four independent, twoinput, nor gates. For the love of physics walter lewin may 16, 2011 duration.

The figure shows a sample layout of cmos 2input nor gate, using singlelayer metal and singlelayer polysilicon. Also create a fulladder implemented by 3 nands and 2 xors. Cmos circuits dissipate power by charging the various load capacitances mostly gate and wire capacitance, but also drain and some source capacitances whenever they are switched. For the output to be equal to vdd, transistors q1 and q2 should be conducting while q3 and q4 must be nonconducting. Gate design the only way to become a good chip designer is to design chips. Static logic is a design methodology in integrated circuit design where there is at all times some mechanism to drive the output either high or low. Input voltages of vsignal1 and vsignal2 must both be low to drive the nor gate output high. How to design a nandnor logic gates layout on vlsi. Nor gates are basic logic gates, and as such they are recognised in ttl and cmos ics. Lab 6 design, layout, and simulation of cmos nandnorxor. You will assemble the nand with an inverter to build an and gate. The truth table of the simple two input nor gate is shown in table.

Cmos gate circuitry logic gates electronics textbook. Cmos nand gate is preferred to cmos nor gate because in pull down network generally used because of easy comparison with ground potential is in series configuration offers less resistancedrain to source. You are required to design a simple cmos circuit consisting of a twoinput nor gate. We need parallel or series connections of nmos and pmos with a nmos source tied directly or indirectly to ground and a pmos source tied directly or indirectly to v dd. Lab 6 design, layout, and simulation of cmos nand nor xor gates and a fulladder. What is the best software to simulate cmos transistors in. This applet demonstrates the static twoinput nor and or gates in cmos technology. This design aims to minimize power dissipation and reduce transistor count while at. A truth table of xor gate can easily be followed to get a mos based circuit for the gate.

Cmos nand gate is preferred to cmos nor gate because in pull down network generally used because of easy comparison with ground potential is in series configuration offers less resistancedrain to. Online schematic capture lets hobbyists easily share and discuss their designs, while online circuit simulation allows for quick design iteration and accelerated learning about electronics. Mostly, we prefer nand gates over nor gates for designing the other basic logic gates. Click the input switches or type the a,b and c,d bindkeys to control the two gates. May 25, 2019 there are different nor gate ic numbers. Layoutschematics for this lab we will be designing and simulating cmos logic gates. Cmos inverter circuit i cmos nand gate i cmos nor gate circuit. You will run the design rule checker on the layout, and will compare the layout with the schematic. To be meaningful, the analysis program has to process a typ. A basic cmos structure of any 2input logic gate can be drawn as follows. The block output logic level is low if the logic levels of any of the gate inputs are 1. Lambdabased designs are scaled to the appropriate absolute units depending on the manufacturing process finally used.

The pdn of two input nor gate is shown in figure below. The circuit is simulated by cmos technology on dsch nor gate circuit. Tutorial on how to design a cmos nand layout using microwind design and simulation tool. A schematic, icon and layout will be created for each gate, and a simulation showing proper operation will be performed for each. The cmos nor block represents a cmos nor logic gate behaviorally. Digital logic nor gate universal gate electrical technology. Apr 18, 2018 design of nand gate in microwind mumbai university. A cmos gate is a system consisting of a pmos pullup network connected to the output 1 or v dd and nmos pulldown network, connected to the output 0 or gnd. Tutorial 1 vlsi electric nandnor layout design youtube. Whenever a singlethrow switch or any other sort of gate output incapable of both sourcing and sinking current is being used to drive a cmos input, a resistor connected to either v dd or ground may be used to provide a stable logic level for the state in which the driving devices. Tutorial on how to design a cmos nor layout using microwind design and simulation tool. What is the best software to simulate cmos transistors in a. You are required to show the layout plan view of the circuit, after calculating the aspect ratio w.

Nor gates are also available in the cmos ic packages. Electric software used to lay out cmos circuits magic software used to lay out cmos circuits. Cadence tutorial layout of cmos nand gate duration. Lab6 designing nand, nor, and xor gates for use to design full. Up until this point, our analysis of transistor logic circuits has been limited to the ttl design paradigm, whereby bipolar transistors are used, and the general. Oct 10, 2016 tutorial on how to design a cmos nor layout using microwind design and simulation tool. Keep the nmos size the same, but change the pmos to 2010.