What is positive logic and gate?

What is positive logic and gate?

Positive Logic OR gate. The Positive Logic OR gates output achieves its ACTIVE state, (HIGH), when “one or more of its inputs” achieve their ACTIVE state, (HIGH). Negative Logic OR gate. The Negative Logic OR gates output achieves its ACTIVE state, (LOW), when “all of its inputs” achieve their ACTIVE state, (LOW).

WHY IS AND gate equivalent of positive logic or gate in negative logic?

(Hint) To change a positive-logic gate to a negative-logic gate is to complement all inputs and output of the gate at the same time. A positive-logic NAND gate implements the function (xy)’. Hence a negative-logic NAND gate implements ((x’y’)’)’ = (x+y)’, which is NOR function.

What is positive and negative logic gate?

Positive logic is defined as a high voltage level representing a logic 1 and a low voltage level representing a logic 0. Negative logic is the reverse, i.e., a low voltage level represents a logic 1 and a high voltage level represents a logic 0.

Why do we use negative logic?

Negative logic conditions can save you time since, in many cases, negative conditions can accomplish the same result as positive conditions but with fewer steps. That said, negative logic conditions are more difficult to think about and even harder to explain…

Which is a universal logic gate?

A universal gate is a gate which can implement any Boolean function without need to use any other gate type. The NAND and NOR gates are universal gates. In practice, this is advantageous since NAND and NOR gates are economical and easier to fabricate and are the basic gates used in all IC digital logic families.

What does positive logic mean?

1. A logic system in which logic 1 is assigned to the higher voltage and logic 0 to the lower voltage. 2. A logic system in which all the Boolean variables and Boolean functions behave as described.

What is the meaning of negative logic?

Negative Logic is a logical circuitry in which higher voltage level refers to LOW (‘0’ or FALSE) and Lower voltage level refers to HIGH(‘1’ or TRUE)

Why are negative logic and positive logic gates still used?

And negative logic persists today in a few areas, because of the desire to retain compatibility with older (sometimes MUCH older) circuits – it is still seen in many Reset circuits (frequently active-low) and DDR DRAM memory control signals among others. Why is AND gate equivalent of positive logic OR gate in negative logic?

What is the relationship between positive and negative logic?

The topics in this mini-series are as follows: The terms positive logic and negative logic refer to two conventions that dictate the relationship between logical values and the physical voltages used to represent them.

Is the gate the same as the diode?

Hence, we conclude that the negative OR gate is the same as the positive AND gate. It may be shown that the above equivalence is true not only for diode logic but is valid irrespective of the hardware used for implementing the circuit.

Is the TTL NAND gate a negative logic gate?

As another answer says, some technologies like the TTL NAND gate allowed both AND and OR logic to be built using the same gate; understanding them required a certain flexibility to think in negative logic!