摘要:
http://wiki.answers.com/Q/What_are_the_differences_between_SRAM_and_DRAMSRAM(Static Random Assessable Memory)-where the wordstaticindicates that it, does not need to be periodically refreshed, as SRAM uses bistable latching circuitry (i.e.,flip-flops) to store each bit. Each bit is stored as a volta 阅读全文
摘要:
http://vhdlguru.blogspot.com/2010/04/difference-between-risingedgeclk-and.htmlrising_edge 是非常严格的上升沿,必须从0到1 , (clk'event and clk='1')可以从X到1查看rising_edge原型 FUNCTION rising_edge (SIGNAL s : std_ulogic) RETURN BOOLEAN IS BEGIN RETURN (s'EVENT AND (To_X01(s) = '1') AND ... 阅读全文