許志斌級電氣3班31實驗六8255并行接口應用實驗實驗目的學習并掌握8255A的工作方式及其應用。掌握8255A典型應用電路接法。PC一臺，TD-PITE微機/單片機教學實驗裝置一套。實驗設備并行接口表2-6-1實驗系統中8255A對應得端口地址表信號線A口B口C口控制寄存器IOY00600H0602H0604H0606HIOY10640H0642H0644H0646HIOY20680H0682H0684H0686HIOY306C0H06C2H06C4H06C6H接口實驗的輸入輸出設備實驗內容及環節題目規定：D0~~D7A0A1WRRDCPA0PA1PA2PA3PA4PA5PA6PA7修改圖2-6-2實驗電路，段數碼管的輸入A、B、C、D、E、F、G、DP分別接到8255A的PA7、PA6、PA5、PA4、PA3、PA2、PA1、PA0、上，CS接到IOY3。編程使七段數碼管循環顯示“F~A”“9~0”折十六個數。XD0~~XD7XA1XA2IOW#IOR#IOY3DPGFEDCBA2-6-18255A驅動顯示實驗接線圖按圖2-6-1連接實驗線路圖編寫實驗程序，經編譯、鏈接無誤后裝入系統運行程序，觀察七段數碼管的顯示。STACK SEGMENT STACKDW32DUP(?)STACK ENDSDATA SEGMENTVA1 DBFDH,61H,DBH,F3H,67H,B7H,BFH,E1H,FFH,F7H,EEH,FEH,9CH,FAH,9EH,8EHDATA ENDSCODE SEGMENTASSUMECS:CODE,DS:DATA,SS:STACKSTART: MOV AX,DATAMOV DS,AXMOV DX,06C6HMOV AL,80HOUT DX,ALA1: LEA SI,[VA1+15]MOV CX,10HA2: MOV DX,06C0HMOV AL,[SI]OUT DX,ALCALL DALLYDEC SILOOP A2JMP A1DALLY: PUSH CXMOV CX,0050HA3: MOV AX,0FFFHA4: DEC AXJNZ A4LOOP A3POP CXRETCODE ENDSEND START實驗現象：數碼管從“F~A”“9~0”依次顯示。題目規定：按圖2-6-1接線。編程：當撥動PA0對應得開關K0時，發光二極管全亮；K0撥回原位全滅。當撥動PA7對應得開關K7，兩個發光二極管同時從D7到D0循環亮燈，K7撥回原位全滅。XD0~~XD7XA1XA2IOW#IOR#IOY0D0~~D7A0A1WRRDCSPB0~~PB7PA0~~PA7K0~~K7D0~~D7圖2-6-28255A基本輸入輸出實驗接線圖實驗環節：實驗接線圖如圖2-6-2所示，按圖連接實驗線路圖。編寫實驗程序，經編譯、連接無誤后裝入系統。運行程序，改動撥動開關K0和K7，同時觀察LED顯示，驗證程序功效。STACK SEGMENTDW32DUP(?)STACK ENDSCODE SEGMENTASSUMECS:CODE,SS:STACKSTART: MOV DX,0606HMOV AL,82HOUT DX,ALA1: MOV DX,0602HIN AL,DXTEST AL,01HJNZ A2JZ A3A2: MOV AL,0FFHMOV DX,0600HOUT DX,ALJMP A1A3: MOV AH,00HPUSH AXMOV AL,00HMOV DX,0600HOUT DX,ALPOP AXTEST AL,80HJNZ B1JMP A1B1: MOV BL,0C0HB2: MOV DX,0600HMOV AL,BLOUT DX,ALMOV DX,0602HIN AL,DXTEST AL,80HJZ A3MOV AL,BLROR AL,1ROR AL,1MOV BL,ALCALL DELAYJMP B2DELAY: PUSH CXPUSH AXMOV CX,0060HD1: MOV AX,0FFFHD2: DEC AX` JNZ D2LOOP D1POP AXPOP CXRETCODE ENDSENDSTAR