单行评论

单行注释以两个连字符（--）开头，并一直延伸到该行的末尾。示例：

-- This process models the state register
process(clock, aresetn)
begin
  if aresetn = '0' then         -- Active low, asynchronous reset
    state <= IDLE;
  elsif rising_edge(clock) then -- Synchronized on the rising edge of the clock
    state <= next_state;
  end if;
end process;