Assembler äëÿ íà÷èíàþùèõ


         

Ïåðâàÿ ÷àñòü ïðîãðàììû ïðèìåðà èíèöèàëèçèðóåò


              0028      EE                      OUT  DX,AL
 
                                     ;-----  Ïðèåì ñèìâîëà
 
              0029      BA 03FD                  MOV  DX,SERIAL+5      ; Ðåãèñòð ñîñòîÿíèÿ êàíàëà
              002C                        RECV:
              002C      EC                      IN   AL,DX
              002D      A8 02                   TEST AL,2
              002F      74 FB                   JZ   RECV
              0031      BA 03F8                  MOV  DX,SERIAL
              0034      EC                      IN   AL,DX
 
              0035      CB                      RET
              0036                        ASYNC      ENDP
              0036                        CODE ENDS
                                           END  ASYNC
 
      Ôèã.8.16 Óñòàíîâêà, ïåðåñûëêà è ïîëó÷åíèå äàííûõ ïî
                      àñèíõðîííîìó êàíàëó (ïðîäîëæåíèå)
 
      Ïåðâàÿ ÷àñòü ïðîãðàììû ïðèìåðà èíèöèàëèçèðóåò ìèêðîñõåìó ACE
    8250. Ïåðâûì äåëîì ïðîãðàììà íàñòðàèâàåò ñêîðîñòü ðàáîòû àäàïòåðà.
    Çíà÷åíèå äåëèòåëÿ, ðàâíîå 384, óñòàíàâëèâàåò ñêîðîñòü 300 áîä.
    Îáðàòèòå âíèìàíèå, ÷òî ïåðåä çàïèñüþ çíà÷åíèÿ äåëèòåëÿ ïðîãðàììà
    çàíîñèò 1 â áèò 7 óïðàâëÿþùåãî ðåãèñòðà ïî àäðåñó 3FBH.
    Îêîí÷àòåëüíûé âûâîä â ïîðò 3FBH çàäàåò õàðàêòåðèñòèêè ëèíèè.  ýòîì

             Microsoft (R) Macro Assembler Version 5.00                1/1/80 04:05:50
             Ôèã. 8.17 Îáðàáîòêà ïðåðûâàíèé îò ïîñëåäîâàòåëüíîãî êàíàëà  Page     1-1
 
 
                                           PAGE ,132
                                           TITLE      Ôèã. 8.17 Îáðàáîòêà ïðåðûâàíèé îò ïîñëåäîâàòåëüíîãî êàíàëà
 
              0000                        ABS0 SEGMENT AT 0
              002C                              ORG  0BH*4
              002C                        ASYNC_INTERRUPT LABEL  WORD
              002C                        ABS0 ENDS
 
              0000                        STACK      SEGMENT STACK

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