SRFF = SR flipflop SRFF和SR latch有何区别？

SRFF = SR flipflop SRFF和SR latch有何区别？
答：FUNCTION SRFF (S,  R,  CLK,  CLRN,  PRN) RETURNS (Q);
//VHDL Component Declaration:
COMPONENT SRFF
PORT (s : IN STD_LOGIC;
r : IN STD_LOGIC;
clk : IN STD_LOGIC;
clrn: IN STD_LOGIC;
prn : IN STD_LOGIC;
q : OUT STD_LOGIC);
END COMPONENT;
FUNCTION LATCH (D,  ENA)
RETURNS (Q);
//VHDL Component Declaration:
COMPONENT LATCH
PORT (d : IN STD_LOGIC;
ena: IN STD_LOGIC;
q : OUT STD_LOGIC);
END COMPONENT;
不同点在于SRFF是一个触发器,  而LATCH只是一个锁存器,  更详细的真值表可以从软件的HELP文档中可以查到.