第三章?tīng)顟B(tài)機(jī)設(shè)計(jì)

1、第第 三三 章章為什么要使用狀態(tài)機(jī)為什么要使用狀態(tài)機(jī)FSMz涉及語(yǔ)法復(fù)習(xí) TYPE語(yǔ)句語(yǔ)句用法如下：用法如下： TYPE 數(shù)據(jù)類型名數(shù)據(jù)類型名 IS 數(shù)據(jù)類型定義數(shù)據(jù)類型定義 OF 基本數(shù)據(jù)類型基本數(shù)據(jù)類型; 或或 TYPE 數(shù)據(jù)類型名數(shù)據(jù)類型名 IS 數(shù)據(jù)類型定義數(shù)據(jù)類型定義 ;用戶自定義的數(shù)據(jù)類型用戶自定義的數(shù)據(jù)類型類型定義語(yǔ)句類型定義語(yǔ)句TYPETYPETYPE m_state IS ( st0，st1，st2，st3，st4，st5 ) ; SIGNAL present_state，next_state : m_state ;布爾數(shù)據(jù)類型的定義語(yǔ)句是：布爾數(shù)據(jù)類型的定義語(yǔ)句是： TYP

2、E BOOLEAN IS （FALSE，TRUE） ； TYPE my_logic IS ( 1 ，Z ，U ，0 ) ; SIGNAL s1 : my_logic ; s1 CS=1; A0=0; RC=0; LOCK=0; next_state CS=0; A0=0; RC=0; LOCK=0; next_state CS=0; A0=0; RC=0; LOCK=0; IF (STATUS=1) THEN next_state = st2;ELSE next_state CS=0; A0=0; RC=1; LOCK=0; next_state CS=0; A0=1; RC=1; LOCK=

3、1; next_state next_state = st0; END CASE ; END PROCESS COM ; REG：PROCESS (CLK) BEGIN IF ( CLKEVENT AND CLK=1) THEN current_state = next_state; END IF; END PROCESS REG; LATCH： PROCESS (LOCK) BEGIN IF LOCK=1 AND LOCKEVENT THEN REGL = D ; END IF; END PROCESS ; Q = REGL; K12X8 CS=1; A0=0; RC=0; LOCK=0;

4、next_state CS=0; A0=0; RC=0; LOCK=0; next_state CS=0; A0=0; RC=0; LOCK=0; IF (STATUS=1) THEN next_state = st2; ELSE next_state CS=0; A0=0; RC=1; LOCK=0; next_state CS=0; A0=1;RC=1; LOCK=1; next_state next_state = st0; END CASE ;END PROCESS COM ;接下頁(yè)接下頁(yè) REG：PROCESS (CLK) BEGIN IF ( CLKEVENT AND CLK=1)

5、 THEN current_state = next_state; END IF; END PROCESS REG; LATCH： PROCESS (LOCK) BEGIN IF (LOCK=1 AND LOCKEVENT) THEN REGL = D ; END IF; END PROCESS ; Q = REGL; K12X8 next_state next_state IF (STATUS=1) THEN next_state = st2; ELSE next_state next_state next_state next_state = st0; END CASE ; OUT4 =

6、current_state(4 DOWNTO 1); END PROCESS COM1 ; REG: PROCESS (CLK) - 時(shí)序進(jìn)程時(shí)序進(jìn)程 BEGIN IF ( CLKEVENT AND CLK=1) THEN current_state = next_state; END IF; END PROCESS REG; LK = current_state(1) ; 接下頁(yè)接下頁(yè) LATCH1 : PROCESS ( LK ) - 數(shù)據(jù)鎖存器進(jìn)程數(shù)據(jù)鎖存器進(jìn)程 BEGIN IF LK=1 AND LKEVENT THEN REGL = D ; END IF； END PROCESS ;

7、 Q = REGL; END behav;接上頁(yè)接上頁(yè)狀態(tài)機(jī)工作時(shí)序圖狀態(tài)機(jī)工作時(shí)序圖（2）順序編碼）順序編碼編碼方式編碼方式【例】【例】.SIGNAL CRURRENT_STATE,NEXT_STATE: STD_LOGIC_VECTOR(2 DOWNTO 0 );CONSTANT ST0 : STD_LOGIC_VECTOR(2 DOWNTO 0) := 000 ;CONSTANT ST1 : STD_LOGIC_VECTOR(2 DOWNTO 0) := 001 ;CONSTANT ST2 : STD_LOGIC_VECTOR(2 DOWNTO 0) := 010 ;CONSTANT ST3 : STD_LOGIC_VECTOR(2 DOWNTO 0) := 011 ;CONSTANT ST4 : STD_LOGIC_VECTOR(2 DOWNTO 0) := 100 ;狀態(tài)機(jī)剩余狀態(tài)處理狀態(tài)機(jī)剩余狀態(tài)處理狀 態(tài)順 序 編 碼st0000st1001st2010st3011st4100st_ilg1101st_ilg2110st_ilg3111狀態(tài)機(jī)一位熱碼編碼方式的選擇狀態(tài)機(jī)一位熱碼編碼方式的選擇狀態(tài)圖狀態(tài)圖考試安排z時(shí)間：時(shí)間：6月月20號(hào)（下周周一）號(hào)（下周周一）z地點(diǎn)：地點(diǎn)：103z形式：開(kāi)卷（只帶一本課本）形式：開(kāi)