## What is a VHDL code?

The **VHSIC Hardware Description Language** (VHDL) is a hardware description language (HDL) that can model the behavior and structure of digital systems at multiple levels of abstraction, ranging from the system level down to that of logic gates, for design entry, documentation, and verification purposes.

## How do you write XOR in VHDL?

The basic "xor" gate: truth table equation symbol a b **| c —-+– c <= a xor b**; VHDL c = (a and not b) or (not a and b); 0 0 | 0 0 1 | 1 c = a ^ b; 1 0 | 1 1 1 | 0 c = xor(a,b) Easy way to remember: "eXclusive or" not 11, or odd number of ones.

## How do you write NOT gate in VHDL?

VHDL Code for NOT Gate: all; entity **not_gate** is port(A : in std_logic; Y : out std_logic); end not_gate; architecture notLogic of not_gate is begin Y <= not(A) ; end notLogic; First, the libraries are imported. library IEEE; use IEEE. std_logic_1164.