第八章_状态机设计.ppt

8.2.2 单进程Moore型有限状态机 图8-8 例8-4单进程状态机工作时序 8.2.2 单进程Moore型有限状态机 图8-9 对应于例8-4的2进程状态机工作时序图 8.3 Mealy型有限状态机的设计 【例8-5】 LIBRARY IEEE; USE IEEE.STD_LOGIC_1164.ALL; ENTITY MEALY1 IS PORT ( CLK ,DATAIN,RESET : IN STD_LOGIC; Q : OUT STD_LOGIC_VECTOR(4 DOWNTO 0)); END MEALY1; ARCHITECTURE behav OF MEALY1 IS TYPE states IS (st0, st1, st2, st3,st4); SIGNAL STX : states ; BEGIN COMREG : PROCESS(CLK,RESET) BEGIN --决定转换状态的进程 IF RESET =1 THEN STX = ST0; ELSIF CLKEVENT AND CLK = 1 THEN 接下页 CASE STX IS WHEN st0 = IF DATAIN = 1 THEN STX = st1; END IF; WHEN st1 = IF DATAIN = 0 THEN STX = st2; END IF; WHEN st2 = IF DATAIN = 1 THEN STX = st3; END IF; WHEN st3= IF DATAIN = 0 THEN STX = st4; END IF; WHEN st4= IF DATAIN = 1 THEN STX = st0; END IF; WHEN OTHERS = STX = st0; END CASE ; END IF; END PROCESS COMREG ; COM1: PROCESS(STX,DATAIN) BEGIN --输出控制信号的进程 CASE STX IS WHEN st0 = IF DATAIN = 1 THEN Q = 10000 ; ELSE Q=01010 ; END IF ; WHEN st1 = IF DATAIN = 0 THEN Q = 10111 ; ELSE Q=10100 ; END IF ; WHEN st2 = IF DATAIN = 1 THEN Q = 10101 ; ELSE Q=10011 ; END IF ; WHEN st3= IF DATAIN = 0 THEN Q = 11011 ; ELSE Q=01001 ; END IF ; WHEN st4= IF DATAIN = 1 THEN Q = 11101 ; ELSE Q=01101 ; END IF ; WHEN OTHERS = Q=00000 ; END CASE ; END PROCESS COM1 ; END behav; 接上页 图8-10 例8-5状态机工作时序图 【例8-6】 MEALY2 LIBRARY IEEE; --MEALY FSM USE IEEE.STD_LOGIC_1164.ALL; ENTITY MEALY2 IS PORT ( CLK ,DATAIN,RESET : IN STD_LOGIC; Q : OUT STD_LOGIC_VECTOR(4 DOWNTO 0)); END MEALY2; ARCHITECTURE behav OF MEALY2 IS TYPE states IS (st0, st1,