Basics1

Entity
Entity describes the chip as a "black box", showing only the inputs and outputs.

Architecture
Architecture describes the chip as a "transparent box", showing all the wires and operations of the chip.

Example chip "BASICS1"
--- -- Basics 1 -- -- Entity and architecture -- -- Copyright: Daniel Tisza, 2013, GPLv3 or later --- library ieee; use ieee.std_logic_1164.all; use ieee.numeric_std.all;

-- Describe the I/O of this "chip" entity basics1 is

port(		reset : in std_logic;		clk : in std_logic;		output : out std_logic	);

end basics1;

-- Describe the contents of this "chip" architecture rtl of basics1 is	-- Internal signals signal not_really_used : std_logic;

begin

-- Operations inside the "chip" output <= '1'; end architecture;