【正文】 ADC0809 芯片 ADC0809 是美國國家半導體公司生產(chǎn)的 CMOS 工藝 8 通道， 8 位逐次逼近式 A/D 模數(shù)轉(zhuǎn)換器。 3）轉(zhuǎn)換時間為 100μs(時鐘為 640kHz 時 )， 130μs（時鐘為 500kHz 時） 4）單個 +5V 電源供電 5）模擬輸入電壓范圍 0～ +5V，不需零點和滿刻度校準。下面說明各引腳功能。 START： A/D 轉(zhuǎn)換啟動脈沖輸入端，輸入一個正脈沖（至少 100ns 寬）使其啟動（脈沖上升沿使 0809 復位，下降沿啟動 A/D 轉(zhuǎn)換）。 CLK：時鐘脈沖輸入端。 GND：地。下降沿啟動 A/D 轉(zhuǎn)換，之后 EOC 輸出信號變低，指示轉(zhuǎn)換正在進行。數(shù)據(jù)傳送的關鍵問題是如何確認 A/D 轉(zhuǎn)換的完成，因為只有確認完成后，才能進行傳送?？蓳?jù)此設計一個延時子程序， A/D 轉(zhuǎn)換啟動后即調(diào)用此子程序，延遲時間一到，轉(zhuǎn)換肯定已經(jīng)完成了，接著就可進行數(shù)據(jù)傳送。 不管使用上述哪種方式，只要一旦確定轉(zhuǎn)換完成，即可通過指令進行數(shù)據(jù)傳送。 l ~ P2 口 8 位雙向口線（在引腳的 21~28 號端子）。 P1 口 只做 I/O 口使用：其內(nèi)部有上拉電阻。用公式 y=+（ 360n/m）可計算出正弦波的輸出值 .每產(chǎn)生一個正弦波測量一次頻率 . 源代碼 C8255 EQU 0F22BH 。8255 PC 口地址 KEYVAL EQU 30H 。讀鍵子程序 LCALL DISP 。方波發(fā)生器 MOV R2,50 FANGBODI: MOV A,0H MOV DPTR,0F218H MOVX DPTR,A SETB 。等待 EOC 變低 MOV DPH,0F2H MOVX A,DPTR 。判斷鍵值 CJNE R2,25,FANGBOGAO LCALL DISPFANGBO 。等待 EOC 變低 MOV DPH,0F2H MOVX A,DPTR 。初始化 MOV DPTR,0F230H MOVX DPTR,A 。讀 A_D 數(shù)據(jù) MOV P1,A MOV R4,A MOV R1,A DJNZ R1,$ INC R5 LCALL RD_KB LCALL DISP CJNE R6,39H,SANJIAO CJNE R5,128,CC LCALL DISPZHENGXIAN CC:CJNE R5,0,DD LCALL DISPZHENGXIAN DD:SJMP SIN SANJIAO:CJNE R6,77H,NEXT1 。啟動 A_D JNB ,$ 。數(shù)據(jù)輸出 MOV R4,A MOV R1,A DJNZ R1,$ LCALL RD_KB LCALL DISP POP ACC CJNE R6,77H,NEXT1 CJNE A,44H,SJUP LCALL DISPSANJIAO 。啟動 A_D JNB ,$ 。數(shù)據(jù)輸出 MOV R4,A MOV R1,A DJNZ R1,$ LCALL RD_KB LCALL DISP POP ACC CJNE R6,77H,NEXT1 常州大學硬件實習報告 第 19 頁 共 31 頁 CJNE A,0H,SJDO LCALL DISPSANJIAO SJMP SANJIAO NEXT1:RET DISPZHENGXIAN: 。段選 LCALL DINGSHI MOV DPTR,P8255C MOV A,10H MOVX DPTR,A MOV DPTR,P8255A MOV A,NUMS2 MOVX DPTR,A LCALL DINGSHI MOV DPTR,P8255C MOV A,18H MOVX DPTR,A MOV DPTR,P8255A MOV A,NUMS3 MOVX DPTR,A POP ACC RET DISPSANJIAO: LCALL DINGSHI PUSH ACC MOV A,R4 MOV B,4 DIV AB MOV B,5 常州大學硬件實習報告 第 21 頁 共 31 頁 MUL AB ADD A,100 MOV R0,A MOV A,B ADDC A,0 MOV B,A MOV A,R0 ANL A,0FH MOV DPTR,LEDSEG MOVC A,A+DPTR MOV NUMS1,A MOV A,R4 MOV B,4 DIV AB MOV B,5 MUL AB ADDC A,100 MOV R0,A MOV A,B ADDC A,0 MOV B,A MOV A,R0 SWAP A ANL A,0FH MOV DPTR,LEDSEG MOVC A,A+DPTR MOV NUMS2,A MOV A,R4 MOV B,4 DIV AB MOV B,5 MUL AB ADDC A,100 MOV R0,A MOV A,B ADDC A,0 MOV B,A MOV A,R0 ANL B,0FH MOV A,B MOV DPTR,LEDSEG MOVC A,A+DPTR 常州大學硬件實習報告 第 22 頁 共 31 頁 MOV NUMS3,A MOV DPTR,P8255C MOV A,08H MOVX DPTR,A MOV DPTR,P8255A MOV A,NUMS1 MOVX DPTR,A LCALL DINGSHI MOV DPTR,P8255C MOV A,10H MOVX DPTR,A MOV DPTR,P8255A MOV A,NUMS2 MOVX DPTR,A LCALL DINGSHI MOV DPTR,P8255C MOV A,18H MOVX DPTR,A MOV DPTR,P8255A MOV A,NUMS3 MOVX DPTR,A POP ACC RET DISPFANGBO: LCALL DINGSHI PUSH ACC MOV A,R4 MOV B,5 DIV AB ADD A,12 ANL A,0FH MOV DPTR,LEDSEG MOVC A,A+DPTR MOV NUMS1,A MOV A,R4 MOV B,5 DIV AB ADD A,12 SWAP A ANL A,0FH MOV DPTR,LEDSEG MOVC A,A+DPTR 常州大學硬件實習報告 第 23 頁 共 31 頁 MOV NUMS2,A MOV DPTR,P8255C MOV A,08H MOVX DPTR,A MOV DPTR,P8255A MOV A,NUMS1 MOVX DPTR,A LCALL DINGSHI MOV DPTR,P8255C MOV A,10H MOVX DPTR,A MOV DPTR,P8255A MOV A,NUMS2 MOVX DPTR,A LCALL DINGSHI POP ACC RET DISP:MOV DPTR,P8255A 。延時消抖 MOV DPTR,P8255B 。等待鍵釋放 MOVX A,DPTR CJNE A,0FFH,KEYWAIT KEYEXIT:RET DINGSHI:MOV R0,5 。t appealed against the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any pensation awarded to you as a result of your failure to appeal. Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are plaining about happened. If your application is received after this time limit, the tribunal will not usually accept it. 常州大學硬件實習報告 第 28 頁 共 31 頁 If you are worried about how the time limits apply to you, take advice from one of the anisations listed under Further help. Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation. Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the anisations listed under Further help. If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your pensation if you win the case. This is known as a damagesbased agreement. In England and Wales, your solicitor can39。s 150th anniversary celebrations and will attend City39。s governing body, has also ordered an immediate investigation into the referee39?；蛟S是愧疚于自己似乎把轉(zhuǎn)瞬即逝的很多個不同的日子過成了同一天的樣子；或許是追溯過去，對自己那些近乎偏執(zhí)的怪異信念的醒悟，這些天以來，思緒一直很凌亂，在腦海中不斷糾纏。 Junior high school, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isn39。t remember his appearance. 童年時，覺得壓歲錢和新衣服是過年必備，但是隨著年齡的推進，會越來越發(fā)現(xiàn)，那些東西根本就可有可無；初中時，以為要有一場暗戀才意味著真正的成長，但三年過去后，自己心平氣和的寫同學錄的時候，突然就發(fā)現(xiàn)是不是真正的成長了，好像并沒有那么重要了；然后到了高中，覺得非要吐露出自己的心聲才能為高中生涯里的懵懂情愫劃上一個句點，但畢業(yè)晚會的時候最終還是被梗塞在了咽喉，后來再次站在他曾經(jīng)揮汗如雨的球場，看著他投過籃球的球框時，突然間發(fā)現(xiàn)自己已經(jīng)想不起他的容顏。想要的，不想要的，界限明確，好像沒有什么可以