SWITCH LEVEL MODELLING 2X4

1. Switch Level Modeling:-
The switch level of modeling provides a level of abstractionbetweenthe
logic and analog-transistor levels of abstraction, describing the
interconnectionof transmission gates which are abstractionsof
individual MOS and CMOS transistors. The switch level transistors are
modeled as being either on or off, conducting or not conducting. Further,
the values carried by the interconnectionsare abstracted from the whole
range of analog voltages or currentsto a small number of discretevalues.
These values are referred to as signal strengths.
NOT GATE NAND GATE
SYNTEX:-
Nmos n1(output,data,control)
Pmos p1(output,data,control)

2. DECODER
In digital electronics,a binary decoder is a combinational logic circuit that
converts binary information from the n coded inputs to a maximum of
2n
unique outputs. They are used in a wide variety of applications, including
data DE multiplexing, seven segmentdisplays,and memoryaddress
decoding.

3. BLOCK DIAGRAM USING BASIC GATES:-
TRUTH TABLE:-

4. PROGRAM:-
module notgate1(x,y);
input x;
output y;
supply0 gnd;
supply1 vdd;
pmos x1(y,vdd,x);
nmos x2(y,gnd,x);
endmodule
module andgate(a,b,y);
input a,b;
output y;
wire w,w1;
supply0 gnd;
supply1 vdd;
pmos y1(w,vdd,a);
pmos y2(w,vdd,b);
nmos y3(w1,gnd,b);
nmos y4(w,w1,a);
notgate1 y5(w,y);
endmodule
module decoder(a,b,i);
input a,b;
output [3:0]i;
wire abar,bbar;
notgate1 z1(a,abar);
notgate1 z2(b,bbar);
andgate z3(abar,bbar,i[0]);
andgate z4(abar,b,i[1]);
andgate z5(a,bbar,i[2]);
andgate z6(a,b,i[3]);
endmodule
module decoder_test();
reg a,b;
wire [3:0]i;
decoder d1(a,b,i);
initial
begin
a=1'b0;b=1'b0;
#5 a=1'b0;b=1'b1;
#5 a=1'b1;b=1'b0;
#5 a=1'b1;b=1'b1;
#5 $stop;
end
endmodule

5. WAVEFORM:-

6. SCHEMATIC DIAGRAM:-

7. PROGRAM IN CADENCE:-