NAND Gate

Information

../../../_images/NAND.png

A digital NAND gate is a combination of an AND gate followed by a NOT gate. It outputs a logic low (0) only if all of its inputs are high; otherwise, the output is logic high (1). It performs the negation of the logical conjunction.

The truth table for a 2-input NAND gate is:

In1

In2

Out

0

0

1

0

1

1

1

0

1

1

1

0

Ports

  • In1: First digital input

  • In2: Second digital input

  • Out: Digital output (result of NOT(In1 AND In2))

Model

The NAND model implements a standard 2-input digital NAND logic gate.

A digital NAND gate outputs logic 0 only when both inputs are logic 1.

Attributes:

  • In1 (dsignal): First input digital signal

  • In2 (dsignal): Second input digital signal

  • Out (dsignal): Output digital signal

Methods:

digital(): Performs the logical NAND operation:

\[\text{Out} = \lnot (\text{In1} \land \text{In2})\]
from pyams.lib import dsignal, model, circuit

class NAND(model):
    """ Digital NAND gate model """
    def __init__(self, In1, In2, Out):
        # Digital Signal declarations
        self.In1 = dsignal(direction='in', port=In1)
        self.In2 = dsignal(direction='in', port=In2)
        self.Out = dsignal(direction='out', port=Out)

    def digital(self):
        """ Perform NAND operation """
        self.Out += ~(self.In1 & self.In2)

Command syntax

The syntax for defining a NAND gate in a PyAMS simulation:

# Import the model
from pyams.models import NAND

# NANDname: name of the NAND gate instance
# In1, In2, Out: digital signal ports
NANDname = NAND(In1, In2, Out)