The always procedural block statement is executed repeatedly throughout the simulation.

Syntax:

always [ sensitivity_list ]
  statement 

Description:

The always procedural block statement is executed continuously during simulation. When the last statement in the always block is reached, the execution continuous with the first statement in the block.

The sensitivity_list controls when all statements in the block will start to be evaluated.

An always block containing more than one statement must enclose the statements in a begin-end or fork-join block (see Begin and Fork).

Example:

always #10 Clk = !Clk;

always @(posedge Clk or negedge Reset)
begin
  if (!Reset)
    Q <= 0;
  else
    Q <= D;
end

Notes:

• The always block should contain at least one procedural timing control because otherwise it may hang the simulation.

See also:

Begin, Fork, Initial, Sensitivity list