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Drive XOR from NAND or NOR gates -

Step 2 involves Invert of A and invert of B. check circuit for nand to inverter

So the digital logic circuit to drive XOR from NAND is below.

Some of the most important interview questions includes the conversion of gates. In this section we are going to discuss logic to drive XOR gate from using only NAND gates. Some other topics that we have already discussed listed below:

Convert NAND to Inverter logic

Drive XOR gate from NORgate.

Lets start the discussion with truth tables of XOR and NAND.

Convert NAND to Inverter logic

Drive XOR gate from NORgate.

Lets start the discussion with truth tables of XOR and NAND.

A

B

Y

0

0

0

0

1

1

1

0

1

1

1

0

A

B

Y

0

0

0

0

1

1

1

0

1

1

1

0

First reformat the XOR equation.

Step 1 :- A'B + AB' = [(A+B')' + (A'+B)'] using theorems T7, T8 & T9

Step 2 :- [((A')'+B')' + (A' + (B')')'] using theorems T7, T8 and T9

Step 1 :-

Step 2 :-

Resources

Verilog RTL code examples for front-end chip design.

Digital Design Topics

Half-adder , full-adder ,

Adder-sub tractor

Stack Organization - LIFO, RPN

Parity Generation and error checking

Binary multiplier circuit.

CMOS introduction

Digital fundamentals -

RTL coding guidelines. ICG cell, Assertions, $assertkill, levels. Chandle

Pipeline vs. Parallel processing.

Verilog RTL code examples for front-

Half-

Adder-

Stack Organization -

Binary multiplier circuit.

CMOS introduction

Digital fundamentals -

RTL coding guidelines. ICG cell, Assertions, $assertkill, levels. Chandle

Pipeline vs. Parallel processing.

XOR Truth Table:-

NAND Truth Table

Interview Questions. Main, FPGA, Digital Fundamentals

LTE - Long Term Evolution topics from here

From Digital Basics section we know the equations for XOR and NAND gates. The equations are also shown below:-

XOR equation = A’B + AB’

NAND equation = A’ + B’

Following are the steps to drive logic for XOR using NAND gates

XOR equation = A’B + AB’

NAND equation = A’ + B’

Following are the steps to drive logic for XOR using NAND gates

Give two ways to convert a two input NAND gate to an inverter

Answer : -

Lets first look at the NAND truth Table below

First Method is connect the 1 bit input to either 'a' or 'b' and connect other to
always ‘1’. Detailed discussion below:-

So for the first method there can be two possible combinations.

First combination:-

For Row’s 3 and 4 Input A is always ‘1’

When Input B = 1 then the output is b= 0.

When Input B = 0 then the output is b=1.

Hence a functionality of an inverter.

Second combination:-

Row 2 and 4 in above table have Input A tied to 0. The polarity of B input is inverted at output.

Discussion on the second method on this link Convert NAND to Inverter logic.

Input a

Input b

Output

Row 1

0

0

1

Row 2

0

1

1

Row 3

1

0

1

Row 4

1

1

0

return to Interview Questions. Main, FPGA, Digital basics.

Computer Organization.

Computer Introduction. Building blocks - ALU, ACC, PC, Registers, Stack Pointer, IR, timing and control unit.

Memory Organization.

Cache memory, fully-associative cache , hardware architecture, match circuit, control circuit. Direct-mapped cache , main memory and discussion.

Interrupt controller, Vectored Interrupt Controller. Interrupt registers

Computer Introduction. Building blocks -

Memory Organization.

Cache memory, fully-

Interrupt controller, Vectored Interrupt Controller. Interrupt registers

5 Steps required to build a functional FPGA load (valid for most EDA flows)

How to implement a Integrated Clock Gating (ICG) cell from vendor library.

CMOS Digital Integrated Circuit design for VLSI.

Interview Questions. Main, FPGA, Digital basics.

Solved Examples for 3 variable Kmaps

1. F(x,y,z) = (0,1,6,7) - Minimization, on this page.

2. F(x,y,z) = (0,1,4,5,6,7) - Minimization from here.

3. F(x,y,z) = (3,4,6,7) - Minimization from here.

4. F(x,y,z) = (0,1,2,3,4,5,6,7) - Minimization from here.

1. F(x,y,z) = (0,1,6,7) -

XOR Truth Table:-

A B Y

0 0 0

0 1 1

1 0 1

1 1 0

0 0 0

0 1 1

1 0 1

1 1 0

XOR equation = A’B + AB’

NOR Truth Table

A B Y

0 0 1

0 1 0

1 0 0

1 1 0

0 0 1

0 1 0

1 0 0

1 1 0

NOR equation = A’ B’

Digital logic gate conversion related interview questions. XOR from NOR., NAND to Inverter and XOR from NAND. Lets start our discussion with conversion for xor from nor gate only. The truth tables of XOR and NOR gates are below.

Check the circuit for NOR to inverter (equivalent of NAND to inverter). So the complete circuit for XOR using NOR gates. Diagram shown above.

Reformat XOR equation by following steps below:

XOR is also know as Exclusive OR.

Step 1 :- A'B + AB' +AA’ + BB’ = [(A’+B') (A+B)] using postulate P4 and theorems T7, T8 and T9

Step 2 :- [(AB)'(A’B’)’] using theorems T7, T8 and T9

In step 2, we do invert of A and invert of B.

XOR is also know as Exclusive OR.

Step 1 :-

In step 2, we do invert of A and invert of B.

Derive XOR by only using NOR gates. Steps

Interview Questions. Main, FPGA, Digital Fundamentals