
		  6.   

		     ͻ
		     ⥬ ஫ DMA
		     ͼ

    ⥪   । 稥  :
ணࠬ㥬 ⥬ ன,  ᯥ稢 প 
⮫쪮 㭪権 DOS  BIOS,    ਪ  ⥬ ணࠬ.
     ਭ樯 ࠡ  ன  ᭮ ࠢ 
ணࠬ஢   ४ , , ᮢ⨬
ணࠬ.
    אַ    (DMA) -  ⮤ ।⢥ 饭 
,  .   ⢥砥 ⮫쪮  ணࠬ஢
DMA:  ன  । ⨯ ।,  砫쭮  
ࠧ ᨢ  .  筮 DMA ᯮ  
ᨢ   ⥬   ன⢠ -뢮.
     묨  ஬  ன⢠ -뢮
⢫  ⥬ 設, "宧鶴" ன  .
 ᯮ짮 ஫ DMA  ६  묨  
 ࠢ ⥬ 設, ..    "宧鶴".  
砭  ⥬ DMA 頥  ࠢ ࠢ
設.
    ⥪  PC AT 砥  ᥡ ⥬ DMA, 
  ஫஢ DMA Intel 8237, ॣ 襣  DMA 
ॣ஢ ࠭ DMA.	 ஫ ᯥ稢 7  DMA.
⥬ ᯥ稢 ।    DMA     
横 DMA, ⠪      横, 室  ⥩ ⥪
 (塠⭮ 設 ).  ⮡ ࠭ ॥⢥
⥬ DMA  PC AT  筮 ⥬  PC XT ᪠஢
"⭮" ஫ DMA  ।  XT ⢫ १
"᫮" ஫ DMA.   裡  ⥬,   ⥪ PC AT ਧ
楫ᮮࠧ ᯮ짮 ப  -뢮  80286, 
  ஬   ⭮ DMA, ।砢訩 
祭  , ⠫ १ࢭ.
    ⥬ DMA  PC AT  a . 6.1.

			   Ŀ
			   	DMA1	 
			   		 
	     DRQ0 >DRQ0   DACK0 > 
   8-	  Ĵ DRQ1 >DRQ1   DACK1 > 
  ࠧ來  DRQ2 >DRQ2   DACK2 > 
       DRQ3 >DRQ3   DACK3 > 
   DMA			   		 	    
		       >HLDA   HRQ	 Ŀ   
		          	   
		       Ŀ	   > ⥬
			   Ŀ   	   	設
			   	DMA2	    	   
			   		    	   
		       >DRQ0   DACK0 	   
	     DRQ5 >DRQ1   DACK1 > 
   16-	  Ĵ DRQ6 >DRQ2   DACK2 > 
   ࠧ來 DRQ7 >DRQ3   DACK3 > 
   	          		 	
    DMA 	   >HLDA   HRQ	 >  墠
		         	  横 設
		      
   ⢥ত 
    墠 横 設

		   . 6.1. ⥬ DMA  PC AT

     ⢫ אַ 㯠   ஫  믮
 ᫥⥫ 権:
    ਭ   (DREQ)  ன⢠ -뢮;
    ନ஢  (HRQ)    墠 設;
    ਭ ᨣ (HLDA), ⢥ত騩 墠 設;
    ନ஢ ᨣ (DACK), ᮮ騩 ன  砫 
묨;
    뤠  祩 , ।祭  ;
    ࠡ ᨣ (MEMR, IOW  MEMW, IOR), ᯥ稢騥 ࠢ
;
     砭 横 DMA   横 DMA,  , 
४ 横.

    Ŀ
    ନ஢  ⨳
     ஫ DMA ᯥ稢 ନ஢
⮫쪮 16  ࠧ冷  .  祬   
(15-8  DMA1  16-9  DMA2)  ६ 横 DMA  設 
㯠  ॣ 襣  DMA    設 ,  
  (7-0  DMA1  8-1  DMA2) 뤠  設 
।⢥  ஫.  ᥬ  ࠧ冷  
ᮤঠ  ॣ ࠭ DMA.  16  ॣ ࠭ DMA
頥,  ࠭ DMA2.   A0  易  DMA2  ᥣ
ᮤন   । ᫮.   砥, 
    ࠧ  ,     ।   ᮢ,
  ⠬ (8 ),  ᫮ (16 );
    ᫮ ᥣ   ᯮ  ⭮ ࠭.
     ࠧ, ஫ DMA  ॣ ࠭ । 24-ࠧ來
,  ᯥ稢 ।   । ᭮ ࠭⢠
16  .
     . 6.2  ⥬ DMA  ।  ⮪
 ନ஢    묨.
								     SA23-
								     SA0
 Ŀ					      Ŀ
    DREQ0/3 Ŀ	HRQ1 	       Ŀ	     A23/17    
  >DMA1>	>  > 
    HLDA1   	  	STB1 ڿ        ࠭ 		       
  >	  > >   DMA	 A16 Ŀ	       
  	     	    DACK0/3       	 >SEL  A16       
  	     	  Ĵٳ            > 
  	     	  	A0/7        ĿA16    	       
  	     	  ͻ    >   	       
  	     	  ͻ	     > 襣      A15/9(8)  
  	      	              > 
   DREQ4   Ŀ 	HRQ2   >   DMA	 		       
 >DMA2Ĵ>   		       
    DREQ5/7 	   	STB2    				       
 >	  >   				       
    HLDA2   	     DACK4	  			    A8(7)/1(0) 
 >	  Ŀ	  > 
   	     	   DACK5/7 	  				       
   	     	  ٺ 				       
   	     	   	A1/8 	   				       
   	     	  ͼ				       
   	     	   	D0/7 	  				       
   	     	  ͼ				      
   	     	     
   

	   . 6.2. ⥬ DMA  ।  ⮪

    ନ஢    ।    । ᫮
  . 6.3.

     24-ࠧ來  - DMA1 - । 
    Ŀ   Ŀ
       ࠭ (8 )   	 DMA (16 )	  
    			         			  
      23<------------> 16      15<--->8 7<---->0 
       

     24-ࠧ來  - DMA2 - । ᫮
    Ŀ   Ŀ  Ŀ
       ࠭ (8 )   	 DMA (16 )	    ᥣ 0
    			         			    	      
      23<------------> 17      16<--->9 8<---->1   	 0   
         

		   . 6.3. ନ஢  

    Ŀ
    -奬 ஫ DMA
      . 6.4 ਢ -奬
஫ DMA,  ᮤন  ᭮  ࠢ:
     ᨭ஭樨  ࠢ, ⢫騩 ७
ᨭ஭  ࠡ뢠騩 譨 ࠢ騥 ᨣ;
     ࠢ , 騩 , । 
஫ DMA ய஬ । 㦨 ᮢ DMA.   ⠪
 ᮤন ॣ ० (MOD), ᯮ㥬  롮 ⨯
। DMA  ६ 㦨;
     ஢ ਮ⮢, 㦠騩 ࡨ஬  ६
室 ᮢ DMA.

    Ŀ
     ஫஢ DMA
      ஫ 1 (0, 1, 2  3)
।祭  믮  । DMA  8-ࠧ來묨 ⠬
(  64  ).     ஫ 2 (4, 5, 6, 7)
 5, 6  7 ।祭   ᫮  16-ࠧ來묨 ⠬
(  128  ).   ⫨稥  ய ⥬ DMA
। ᫮ ⮫쪮  ⭮ ࠭ .   4 ᯮ 
᪠  ꥤ  ஫஬ 2.   ࠧ,  
 0-3  ஫ 1 ࠡ뢠 १  4 ஫ 2.	
ਢ  ⮬,    ஫ 1 ( 0, 1, 2  3)
 	᮪ ਮ⮬  ࠢ   ஫ 2
( 5, 6, 7).  ।  ஫஢ DMA ਢ
 ⠡.  6.1.

       . 6.1. ।  ஫஢ DMA
      Ŀ
            ᯮ짮  AT	     
      Ĵ
         0*      		     
      Ĵ
         1*       䥩 SDLC   
      Ĵ
         2*        	     
      Ĵ
         3*      		     
      Ĵ
         4       ᯮ  ᪠- 
                 ஢ ஫஢      
      Ĵ
         5**     		     
      Ĵ
         6**     		     
      Ĵ
         7**     		     
      
     *	8-ࠧ來 .
     ** 16-ࠧ來 .

    Ŀ
     ࠭ 
      ࠭  室   
ᮤন ᥬ  ࠧ冷 24-ࠧ來 .	 
஫ࠬ DMA  ।  (24-ࠧ來)   
DMA.   ⠡. 6.2 ਢ  ⮢ ॣ஢ ࠭  
DMA.

		  . 6.2.  ⮢ ॣ஢ ࠭
		 Ŀ
		          	  
		    DMA       ॣ ࠭  
		 Ĵ
		    0	       087h		  
		 Ĵ
		    1	       083h		  
		 Ĵ
		    2	       081h		  
		 Ĵ
		    3	       082h		  
		 Ĵ
		    4	         -		  
		 Ĵ
		    5	       08h		  
		 Ĵ
		    6	       089h		  
		 Ĵ
		    7	       08Ah		  
		 Ĵ
		   08Fh *		  
		 

    * ন ॣ ࠭  楫 ॣ樨  
ࠢ 00h.

    Ŀ
     ⮢ 
      ⠡. 6.3 ਢ  ⮢ - ॣ஢
   ࠢ/ﭨ ஫஢ DMA,  ⠪ ଠ ॣ஢.

		      . 6.3.  ⮢
 Ŀ
  㭪樨 ॣ஢	     ଠ	 ⮢ ⥭/
 			    	    Ĵ 	    
 			    	      DMA1  	DMA2   	    
 Ĵ
   ﭨ (STAT)   8      008h  	0D0h    ⥭     
  (Read Status Register)   	    	     	       	    
    (CR)	      8    	     	             
  (Write Command Register) 	    	     	       	    
 Ĵ
   ० (MOD)       6      00Bh  	0D6h         
  (Write Mode Register)    	    	     	       	    
   ० (MOD) *** 	    	     	        ⥭     
  (Read Mode Register)     	    	     	       	    
 Ĵ
    ࠧ冷  4      00Ah  	0D4h         
  ॣ ᪨	    	    	     	       	    
  (Write Single Mask	    	    	     	       	    
   Register)		    	    	     	       	    
    (CR) ***    8    	     	        ⥭     
  (Read Command Register)  	    	     	       	    
 Ĵ
    ࠧ冷       4      00Fh  	0DEh         
  ᪨		    	    	     	       	    
  (Write Mask Register)    	    	     	       	    
   ᪨ (MASK) *** 	    	     	        ⥭     
  (Read Mask Register)     	    	     	       	    
 Ĵ
  ணࠬ ॣ	      4      009h  	0D2h         
  ᮢ (REQ)**	    	    	     	       	    
  (Write Request Register) 	    	     	       	    
   ᮢ ***     	    	     	        ⥭     
  (Read Request Register)  	    	     	       	    
 Ĵ
    ⥪騩	      16     000h  	0C0h         
  ॣ  -  0	    	     	       	    
 Ĵ
  騩 ॣ  -   16     000h  	0C0h    ⥭     
   0		    	    	     	       	    
 Ĵ
    ⥪騩	      16     001h  	0C2h         
  ॣ c稪 -	    	    	     	       	    
   0		    	    	     	       	    
 Ĵ
  騩 ॣ 稪   16     001h  	0C2h    ⥭     
  -  0		    	    	     	       	    
 Ĵ
    ⥪騩	      16     002h  	0C4h         
  ॣ  -  1	    	     	       	    
 Ĵ
  騩 ॣ  -   16     002h  	0C4h    ⥭     
   1		    	    	     	       	    
 Ĵ
    ⥪騩	      16     003h  	0C6h         
  ॣ c稪 -	    	    	     	       	    
   1		    	    	     	       	    
 Ĵ
  騩 ॣ 稪   16     003h  	0C6h    ⥭     
  -  1		    	    	     	       	    
 Ĵ
    ⥪騩	      16     004h  	0C8h         
  ॣ  -  2	    	     	       	    
 Ĵ
  騩 ॣ  -   16     004h  	0C8h    ⥭     
   2		    	    	     	       	    
 Ĵ
    ⥪騩	      16     005h  	0CAh         
  ॣ c稪 -	    	    	     	       	    
   2		    	    	     	       	    
 Ĵ
  騩 ॣ 稪   16     005h  	0CAh    ⥭     
  -  2		    	    	     	       	    
 Ĵ
    ⥪騩	      16     006h  	0CCh         
  ॣ  -  3	    	     	       	    
 Ĵ
  騩 ॣ  -   16     006h  	0CCh    ⥭     
   3		    	    	     	       	    
 Ĵ
    ⥪騩	      16     007h  	0CEh         
  ॣ c稪 -	    	    	     	       	    
   3		    	    	     	       	    
 Ĵ
  騩 ॣ 稪   16     007h  	0CEh    ⥭     
  -  3		    	    	     	       	    
 Ĵ
  ६ ॣ    16     00Dh  	0DAh    ⥭     
  (TR)**		    	    	     	       	    
  (Read Temporary Register)	    	     	       	    
  騩 		      *    	     	             
  (Master Clear)	    	    	     	       	    
 Ĵ
   F/F		      *      00Ch  	0D8h         
  (Clear Byte Pointer	    	    	     	       	    
   Flip-Flop)		    	    	     	       	    
  ⠭ F/F ***	    	    	     	        ⥭     
  (Set Byte Pointer	    	    	     	       	    
   Flip-Flop)		    	    	     	       	    
 Ĵ
   ॣ ᪨       *      00Eh  	0DCh         
  (Clear Mask Register)    	    	     	       	    
   稪 MODE ***  	    	     	        ⥭     
  (Clear Mode Counter)     	    	     	       	    
 
 *   ॣ,   ।⢥   ஫ DMA.
 **  ॣ ᯮ ⮫쪮  ० -.
 ***  ॣ   ஫ DMA  ॠ  ஫
 8237   "਩ ஫" STC62C008,  ॠ  設⢥
 ᮢ६ ⮢  .

    Ŀ
    । DMA
     ⥬ DMA  ⢫  묨 
ன⢮ -뢮     ࠧ묨 ᨢ ᠬ .
    ।       ॠ  ⥪ PC AT.
     ।   ன -뢮   ஫ DMA
 ன⢠ -뢮 ᯮ ᨣ DRQx  DAKx  ⠭
裡.	 ன -뢮 㦭 ।   ᫮ ,
 㦤 ᢮  DRQx.  ᫥ 㦤 ஫஬  DAKx
  IOR ன⢮ । ᢮   設   .
 ன -뢮 㦥   ᫮   , 
㦤 ᢮  DRQx.  ᫥ 㦤 ஫஬  DAKx 
 IOW ன⢮ "ࠥ"    設 .

    Ŀ
    ஫ DMA
     ஫ DMA ᯮ  אַ 㯠 
⥬   ६ ᨬ ,  .
       믮  64  横 DMA.  
㠫쭮 ணࠬ஢   ७ 横 DMA
(⮨樠).
     ᭮ ०  짮⥫ ணࠬ஢ ⨯
DMA.
     ᫮    ⥬ ᮥ  ᭮
஫ ⥫ ஫஢ DMA (᪠஢).
     ࠡ    ணࠬ஢ 㠫쭮.

    Ŀ
    㭪樮쭮 祭 뢮 ஫ DMA 
      ⠡. 6.4
ਢ 祭 뢮 ஫ DMA   㭪樮쭮 祭.

       . 6.4. 祭 뢮 ஫ DMA
Ŀ
 祭            㭪樮쭮		    
 뢮       뢮 	祭		    
Ĵ
   CLK        室    : ᨭ஭  
	              ७ 樨, ࠢ	    
	              ᪮ । 	    
Ĵ
  -CS	       室    : ⨢ .    
	              롨ࠥ ஫ DMA  ⢥  
	              ன⢠ -뢮  祭   
	              宫⮣ 横 (SI). 蠥     
	                ய஬  設    
	              				    
Ĵ
   RESET      室   : ⨢ ᮪. 뢠  
	              ॣ , ﭨ,	    
	                ६,  ⠪ ਣ
	              FF  ⠭ ॣ ᪨.   
	              ᫥ ᨣ  ஫ DMA 
	              室  宫⮬ 横	    
Ĵ
   READY      室   : 室 ᯮ 	    
	              ७ ᮢ ⥭ 	    
	                ஫ DMA 	    
	              ᮣᮢ    
	              ਩ ன⢮. READY   
	                 祭 ਮ 
	              ६, 室  	    
	              ⠭/墠. ⨢ ᮪  
Ĵ
   HLDA       室    : ⨢	    
	              ᮪.   CPU 㪠뢠,   
	               CPU ᢮ ⥬ 設    
Ĵ
   DREQ0,     室    DMA: 設,  ன	    
   DREQ1,            㯠 㠫 ᨭ஭륳
   DREQ2,              ਩ ன   
   DREQ3              祭 㦨 ⥬
	              DMA.  䨪஢ ਮ   
	              DREQ0  訩 ਮ, DREQ3 
	              - 訩.  ࠡ뢠     
	              ⥬ ⨢樨 設 DREQ	    
	              ᮮ⢥饣 . DACK	    
	              ⢥ত ᯮ   
	              DREQ. ୮ DREQ		    
	              ணࠬ. 樠	    
	               RESET   設 ⨢ 
	              ᮪ ஢. DREQ 	    
	              ন ⨢   , 
	                ⨢		    
	              ᮮ⢥騩 DACK		    
Ĵ
   DB0,       室-   :  㭠ࠢ 設
   DB1,       室   ६ ﭨﬨ, 易     
   DB2,              ⥬ 設. 室 ࠧ 
   DB3,               ணࠬ஢  ६ 横 
   DB4,              ⥭  뢮 ᮤন	    
   DB5,              ᭮ ॣ, ॣ	    
   DB6,              ﭨ, ६ ॣ   
   DB7               ॣ 稪 ᫮  CPU.	    
	              室 ,  室	    
	              뢠  ६ 横 ,  
	               ࠢ騥 ॣ ஫- 
	               DMA ணࠬ CPU.     
	              ६ 横 DMA 訥 8 ࠧ冷 
	               뤠  設      
	              ஡ ADSTB  譨	    
	              饫.   -  
	                 㯠  -  
	              ஫ DMA  設   ६  
	              ।  .  ।祳
	                室 設     
	              ࠧ   祩   
Ĵ
  -IOR        室-   -: ⨢ .
	       室   㭠ࠢ 設  ६    
	              ﭨﬨ.  宫⮬ 横 -     
	               室 ࠢ騩 ᨣ,     
	              ᯮ㥬 CPU  ⥭	    
	              ࠢ ॣ஢.  ⨢   
	              横 -  室 ࠢ騩    
	              ᨣ, ᯮ㥬 ஫஬   
	              DMA  롮ન   ਩-
	               ன⢠  ६ ।   
	               DMA			    
Ĵ
  -IOW        室-   -: ⨢ .
	       室   㭠ࠢ 設  ६    
	              ﭨﬨ.  宫⮬ 横 -     
	               室 ࠢ騩 ᨣ,     
	              ᯮ㥬 CPU  㧪	    
	              ଠ樨  ஫ DMA. 	    
	              ⨢ 横 -  室	    
	              ࠢ騩 ᨣ, ᯮ㥬    
	              ஫஬ DMA  㧪	    
	                ਩ ன⢮    
	               ६ ।  DMA	    
Ĵ
  -EOP        室-   : 㭠ࠢ 
	       室  ᨣ, ⨢ . 	    
	              ,  蠥	    
	              㦨 ⥬ DMA.	    
	              ஫ DMA ࠧ蠥 譥   
	              ᨣ  㦨	    
	              ⥬ DMA.  ந室	    
	              ⥬ । ᨣ  ஢-
	                室 -EOP. ஫ DMA     
	              ࠡ뢠 ᨣ, 	    
	              稢 砭  (TC)  
	              - .  ⮬ 砥   
	              ᨣ -EOP ।  室.    
	              ࠡ⪠ -EOP,  ७, ⠪
	               譥, ⠢ ஫   
	              DMA   㦨,	    
	                , ᫨ ࠧ襭   
	              ⮨樠,   
	              ॣ  ⥪騥 ॣ . 
	               ᪨  ࠧ TC ॣ   
	              ﭨ ⠭  -EOP   
	               ⥪饣 ⨢ , ᫨ 
	                ணࠬ 	    
	              ⮨樠樨.  ⮬ 砥    
	              ࠧ ᪨ 뢠.	    
	               ६ । -     
	              -EOP ।  室,      
	              ⠭ TC   1.    
	              -EOP ᫥ ᮥ  ᮪    
	              ஢ १ १, ᫨    
	              ᯮ  室, ⮡	    
	              । 訡 室     
	              ᨣ 砭 	    
Ĵ
   0,        室-  :	 4 㭠ࠢ	    
   1,        室  ᨣ  ६ ﭨﬨ	    
   2,                訬 ࠧ鸞	    
   3	              ᭮ 設.	 宫⮬ 横    
	                室  ᯮ 
	              CPU  樨 ࠢ	    
	              ॣ஢ DMA, ⮡ 㧨   
	               .   ⨢ 横    
	               室  뤠 4	    
	                ࠧ鸞	    
Ĵ
   4,        室-  :  4 室 ᨣ      
   5,        室  ६ ﭨﬨ 	    
   6,               訬 ࠧ鸞 ᭮ 設.   
   7	               뤠 ⮫쪮  ६	    
	              㦨 DMA		    
Ĵ
    HRQ       室   :  ᨣ 뤠
	               CPU  ᯮ  ࠢ 
	              墠⮬ ⥬ 設.	    
	              ᫨ ᮮ⢥騩 ࠧ ᪨   
	              襭,  稥 	    
	              ⢨⥫쭮 DREQ ⠢     
	              DMA 뤠 HRQ. ᫥ 뤠 HRQ    
	              ॡ  ࠩ      
	               横 ᨭ஭樨 (TCY),	    
	              ⮡  ⨢ HLDA	    
Ĵ
    DACK0,    室   DMA:  ᨣ	    
    DACK1,           ᯮ  ᮮ饭	    
    DACK2,           㠫쭮 ਨ, 	    
    DACK3               ࠧ蠥 横	    
	              DMA. ⨢ 祭 	    
	              ᨣ ணࠬ.	    
	              樠   	    
	              ⠭   	    
	              ⨢ ஢		    
Ĵ
    AEN       室   :  室	    
	              ࠧ蠥 뤠 ᮤন	    
	              8-ࠧ來 饫 (8 	    
	              ࠧ冷 )  ⥬	    
	               設. AEN ᯮ     
	               ⮬ 砥  饭	    
	              ᯮ짮 ⥬ 設	    
	              㣨 ன⢮  ६	    
	              । DMA. ⨢ ᮪	    
Ĵ
    ADSTB     室   : a⨢ ᮪.	    
	              ᯮ  ஡஢	    
	              襣 ᭮  	    
	              譨 饫.		    
Ĵ
   -MEMR      室   : 室 ᨣ	    
	               ६ ﭨﬨ. ⨢	    
	              . ᯮ  롮ન    
	                 祩     
	               ६ ।  DMA     
	              । -		    
Ĵ
   -MEMW      室   : 室 ᨣ	    
	               ६ ﭨﬨ. ⨢	    
	              . ᯮ       
	                 祩      
	               ६ । 	    
	              DMA  । -	    
Ĵ
    PIN5      室    室   ᥣ	    
	              ᮪ 			    



    Ŀ
     DMA
     ⥬ DMA ।祭  ࠡ   ᭮ 横:
宫⮬  ⨢.   横 -  ᮢ㯭 ண ⢠
 ﭨ.  ⥬ DMA   ᥬ ﭨ,   
ᮮ⢥  ਮ ᨭ஭樨.
    ﭨ SI - ⨢ ﭨ.  ⥬ DMA 室  ⮬
ﭨ,   ⢨⥫ ᮢ  㦨 ⥬
DMA.    ⮬ ﭨ ⥬ DMA  ணࠬ஢.
    ﭨ S0 - ࢮ ﭨ 㦨 ⥬ DMA,
饥  ⢨⥫쭮  (DREQ).	⥬ DMA 訢
ࠧ襭  CPU  墠 ⥬ 設 (HRQ),   祭
⢥ত 墠 (HLDA)   ணࠬ஢.   HLDA
⥬ DMA 室  ࠡ祥 ﭨ.
    ﭨ S1, S2, S3  S4 - ࠡ稥 ﭨ.  稭 ࠡ뢠
᫥ 祭 ⢥ত  CPU.
    ﭨ SW - ﭨ .	室, ᫨  襭
। ॡ  ६, 祬 । 筮.  SW 
""  S2  S3  S4, ᯮ 室 READY DMA.

    Ŀ
     㦨
      ⨢ 横 㦨 ⥬ DMA
     ०.  砭 㦨 ᯮ
 室 ॣ 稪 ᫮  0000  FFFF.   ⮬ 
ᨣ 砭  (TC),   맢 ⮨樠, ᫨
 ணࠬ஢,  ᪨஢    ⢨.
६  TC ࠡ뢠 室 ᨣ -EOP.
     ६ ⮨樠樨 ࢮ砫 祭 ॣ஢ ⥪饣
  稪 ⠭  ᮮ⢥  ॣ஢.
᫥ ⮨樠樨  ⮢ 믮 㣮 㦨
⥬ DMA  ⥫⢠ CPU,  ⮫쪮 㦨 ⮢
DREQ.

      筮 । (Single Transfer Mode)
     -----------------------------------------------
     ⮬ ० ஫ DMA 믮 ⮫쪮  ।.   
稪 ᫮     ।.  DREQ  
⨢,   ⨢ ᮮ⢥騩 DACK.	᫨ DREQ ⨢
 殮 筮 ।, HRQ 室  ⨢ ﭨ 
믮  ।  ᢮ 設 ⥬.  HRQ ᭮ ⠭
⨢ ( ⨢ DREQ)   祭  HLDA 㤥 믮
᫥騩 横 筮 ।.   ࠭ CPU  ⥬
믮   設 横  ।砬 DMA.

      ।  (Blok Transfer Mode)
     -----------------------------------------
     ⮬ ० ।  ଠ樨  ६ 㦨
⥬ DMA.  DREQ   ⨢,    ⨢
DACK.

      ।  ॡ (Demand Transfer Mode)
     ---------------------------------------------------
     ⮬ ० ।  믮   ,   
TC  譨 -EOP,   DREQ ⠭ ⨢.   ࠧ,
।  த   ,  ਩ ன⢮ 
௠ ꥬ .

     ᪠ ० (Cascade Mode)
     ------------------------------
     ० ᯮ ꥤ ᪮쪨 ஫஢ DMA 
७ ᫠ 砥 .
    室 HRQ  室 HLDA  ⥫ ஫஢ ᮥ
ᮮ⢥⢥  室 DREQ  室 DACK ࢨ筮 ஫ DMA .
   ᠬ  ⥫쭮 ன⢠
࠭ १  ਮ 楯 ।饣 ன⢠.
     ࠧ,  ࢨ筮 ஫ DMA,  ஬ 祭
⥫ ஫, ணࠬ  믮 ᪠ ०
 㦨 ⮫쪮  । ਮ ⥫쭮 ன⢠ 
࠭ ᨣ HRQ  CPU  HLDA  CPU.   㣨 ᨣ ᪠
 ࢨ筮 ஫ DMA  ନ஢ 横 ⥬ DMA 
.
     .  6.5  ᪠ ꥤ ஫஢ DMA.  
஢ ⥬.	㣨 ஫ DMA    
⠫  ࢮ ஢.


					    2- ஢
    Ŀ			   Ŀ
    					      DMA    
    			  1- ஢	   	      
     ய- 	 Ŀ	   	      
     	ĴHRQ	DREQĴHRQ       
    		HLDA	DACKHLDA      
    			 	    	   	      
    			    DMA    	   
    	 	    	   Ŀ
			 	    	   	      
			 	DREQHRQ       
			 	DACKĴHLDA      
			 	   	      
			  ࢨ筮	      DMA    
			  ன⢮	   	      
					   
					  ⥫쭮
					    ன⢮

      . 6.5. ᪠ ꥤ ஫஢ DMA

      -
     -------------------
     ० ।祭  ।     ᭮
࠭⢠   㣮  묨 ணࠬ묨  ६묨
⠬,   PC AT  ᯮ.	  ०  ࠡ
⮫쪮 㫥  1-  ஫.   । 樨
ணࠬ ⠭ REQ   0.   祩 -筨
   CAR0,  祩-ਥ -  CAR1.   , ⠭
 ,   ६ ॣ (TR)  ⥬  TR 뢠 
祩-ਥ.   祭 稪 ᫮  1 ⠭ ࠢ
FFFFh, 㦨 稢.

    Ŀ
     ।
        ⨢ ० । 믮
 ࠧ ।.   ,   .  । 
뫠     ਩ ன⢮  ⨢樨 -MEMR
 -IOW.  ।  뫠   ਩ ன⢠ 
  ⨢樨 -MEMW  -IOR.   -  ᥢ।.
⥬ DMA ⢫ ।   ,   
ॠ  -EOP,  ᨣ ࠢ   ਩묨
ன⢠   ⨢묨.  室 READY   .

    Ŀ
    ਮ
     ⥬ DMA   ⨯ ਮ,  
⠭ ணࠬ.	   - 䨪஢ ਮ, 
䨪   ᫥⥫쭮, ᮮ⢥饩 뢠  ஢.
訩 ਮ    3,  訩 ਮ   0.
᫥ 롮 -   㦨 頥 ⥫⢮
⠫    ,  㦨  .
    ன ⨯ ਮ - 横᪨ (. 6.6).  ᫥ 㦥
 ⠭   訬 ਮ⮬ ᮣ᭮ 横.  
横᪮ ਮ  ன⢮, ॡ饥 㦨, ६
㤥 ᯮ ᫥ ࠡ⪨ ᨬ   ਮ
㦨.   ᪫砥  ᥩ ⥬  .


	   1- .	    2- .       3- .


 訩        0		2Į.Ŀ	  3Į.
	       1Į.Ŀ	3   	  0
	       2	   	0	     	  1
 訩        3	   1	     2


    . 6.6. ᪨ ਮ

    Ŀ
     ᠳ
      ६ 横 DMA ஫  饭  
뤠  CPU    (   㯠 
ॣ ࠭ DMA).	祬	ࠧ  15-8 뤠  設
   㯠  譨 饫,     
 設.	  A0-A7 뤠   設
।⢥  ஫ DMA .
     祭 㦨 ० ।    । 
ॡ  ᮢ   ᫥⥫쭮.   讣
⢠ ।   譨  饫  .  
 㦤   ⮫쪮  ७  A7    A8 
筮 ᭮ ᫥⥫쭮,   ࠡ뢠 ﭨ S1
⮫쪮 ⮣,  室  A8-A15  饫.   砥,
  ⥫쭮 㦨 ﭨ S1   ஡ 
 ⮫쪮  ࠧ   256 ।.

    Ŀ
     ஫ DMA
    
     ⮬ ࠣ ਢ ⠫쭮 ᠭ ॣ஢ ஫
DMA.

		    ⥪饣  (CAR)
		   -----------------------------
       16-ࠧ來 ॣ ⥪饣 .   ॣ
࠭ 訥 ࠧ , ᯮ㥬  ६ 㦨 .
 ⮬᪨ 㬥蠥  騢 ᫥  ।, 
஬ 祭    ॣ  ६ ।.
ন ⥪饣 ॣ 뢠  ⠥ ய஬
⭮.

		    ⥪饣 稪 ᫮ (CCR)
		   ------------------------------------
       16-ࠧ來 ॣ ⥪饣 稪 ᫮.  
ॣ । ⢮ ।,  室 믮.
⢮ । 㤥   , 祬 ᫮, ணࠬ㥬 
ॣ (..	 稪  ᫮ 100,  । 㤥 101).
祭 稪 㬥蠥 ᫥  ।,  ஬筮
祭 稪 뢠  ॣ  ६ ।.
     ० ணࠬ஢ ॣ CCR   ⭮ ᠭ 
⠭ ய஬.   㦨, ᫨  
⮨樠, 祭 稪 ᫥ TC ࠢ FFFFH.
     㦨ﬨ,  ய ࠧ蠥 믮
樨, ஬ 祭   稪 ᫮ ࠭ 
ॣ ⥪饣   稪 ᮮ⢥饣 .

	       ॣ   稪 (BAR  CAR)
	      ----------------------------------------------
        ॣ:  ॣ    ॣ
 稪.   ॣ ࠭ 砫 祭 ᮮ⢥
⥪ ॣ஢.   ⮨樠樨  ᯮ 
⠭ ࢮ砫 祭 ⥪ ॣ஢.   ॣ
㦠 ய஬ ࠧ來 ६  ᢮ ⥪騬
ॣࠬ  ० ணࠬ஢.   ᮤন  ॣ஢
.

		       ० (MOD - 00B, 0D6)
		      -------------------------------
       6-ࠧ來 ॣ ० (MOD).    ॣ
ந  ० ணࠬ஢ ⮬, ଠ ண ।⠢
 . 6.7.   0, 1 㪠뢠,  ॣ ०   㦭
ந ,  ࠧ 2-7 - ଠ ।⢥ 
ᮮ⢥饣 ॣ ०.  ॣ ० ࠧ襭 ⮫쪮
 ଠ樨.

ͻ
 7  6  5  4  3  2  1  0 
ͼ  
                  Ŀ
                   00 -  0	 
                   01 -  1	 
                   10 -  2	 
                   11 -  3	 
                  
                  	   横 DMA
             Ŀ
              00 - 		   
              01 -    	   
              10 -   	   
              11 - 饭 	   
              XX - ᫨ ࠧ 6, 7 ࠢ 11 
             
             ⮨樠: 1-; 0-
           
           饭 
      Ŀ
       0 - 㢥祭  
       1 - 㬥襭  
      
        㦨
Ŀ
 00 - ०  ॡ
 01 -  ०	  
 10 -  ०	  
 11 - ᪠ ०	  


    . 6.7. ଠ    ॣ ०

		        (CR - 008, 0D0)
		      ------------------------------
     8-ࠧ來 ॣ ࠢ ﬨ ஫ DMA.  
ணࠬ ய஬  뢠   室 RESET 
 MC (⪠ ⥬).	ଠ   ।⠢  .
6.8.       ⠭ ய஬.

ͻ
 7  6  5  4  3  2  1  0 
ͼ
                        1 - ࠧ襭 ० -
                        0 -  ० -
                       
                     0 -  墠   0
                     1 - ࠧ襭 墠   0
                      - ᫨ ࠧ 0 ᮤন 0
                    
                      0 - ࠧ襭 ஫ DMA
                      1 - ஢ ஫ DMA
                 
              	    0 - ଠ쭠 ᨭ஭
              	    1 - ᦠ ᨭ஭
              	     - ᫨ ࠧ 0 ᮤন 1
              
            	    0 - 䨪஢ ਮ
            	    1 - 横᪨ ਮ
           
        		    0 - 㪮祭   MEMW
        		    1 - 㤫   MEMW
        		     - ᫨ ࠧ 3 ᮤন 1
        
      		    0 - DREQ ⨢ ᮪
      		    1 - DREQ ⨢ 
     
  			    0 - DACK ⨢ 
  			    1 - DACK ⨢ ᮪
  

    . 6.8. ଠ    ॣ 

		        (REQ; 009, 0D2)
		      -------------------------------
    ஫ DMA  ॠ஢    㦨 DMA,
  樨஢ ணࠬ,    DREQ.   
 ᢮ ࠧ  4-ࠧ來 ॣ .   ࠧ
᪨㥬, ਮ  ⠭ ஬ ਮ⮢.
 ࠧ ॣ 뢠  ⠭  ࠢ
ணࠬ  頥  樨 TC  譥 -EOP.   ॣ
頥  RESET.   ⠭  뢠 ணࠬ,
 㦥 ᫮  ᮮ⢥饣 ଠ, ਢ 
. 6.9.   ⮣ ⮡  ணࠬ ,  
室  ० .
         ⠭ ய஬.


ͻ
 7  6  5  4  3  2  1  0 
ͼ  
  ᯮ       Ŀ
		        00 -  0 
		        01 -  1 
		        10 -  2 
		        11 -  3 
		       
		      
		       1 - ⠭ 
		       0 -  
		      

     . 6.9. ଠ ᫮ 

			    ᪨ (MASK)
			   --------------------
       ᢮ ࠧ  4-ࠧ來 ॣ ᪨, 
  ⠭, ⮡ ஢ 室騩 DREQ.   ࠧ
᪨ ⠭,  易    ࠡ뢠 -EOP, ᫨
  ணࠬ஢  ⮨樠 ( ⮬ 砥  -EOP ᪠
 ⠭).
     ࠧ 4-ࠧ來 ॣ ᪨   ⠭ 
襭  ࠢ ணࠬ.   ॣ ⠭  RESET.
 ⮬    DMA,    ࠧ  
ॣ ᪨.   ࠧ쭮 ⠭/ ᪨  
ࠧ쭮 ⠭/ ॣ .  ६  
ࠧ鸞 ᪨   ᠭ ⤥쭮  - Write All Mask
Register Bits.	 ᪨    ⠭ ய஬.
     樠樨 ॣ ᪨ ᯮ  
ଠ⠬, ਢ묨  . 6.10, 6.11.

ͻ
 7  6  5  4  3  2  1  0 
ͼ   
    ᯮ     Ŀ
		        00 -  0 
		        01 -  1 
		        10 -  2 
		        11 -  3 
		       
		         1 - ⠭ 
		         0 -  
		      

    . 6.10. ଠ   ⠭    ࠧ鸞 MASK
	       (00A, 0D4)


ͻ
 7  6  5  4  3  2  1  0 
ͼ
   ᯮ           1 - ⠭   0
		            0 -    0
		           
		        	1 - ⠭   1
		        	0 -    1
		        
		      	1 - ⠭   2
		      	0 -    2
		     
		  		1 - ⠭   3
		  		0 -    3
		  

    . 6.11. ଠ    ଠ樨   ࠧ MASK
	      (00F, 0DE)

		     ﭨ (STAT - 008, 0D0)
		    -----------------------------------
    ন ॣ ﭨ   ⠭ ய஬.
 ᮤন ଠ  ﭨ     ६.
 ଠ 뢠,   ⨣  稪 (..
ᣥ஢ TC)     㤮⢮७  ( .
6.12 ).   0-3 ॣ ⠭  ࠧ,  
TC  ᮮ⢥饣   譨 -EOP.   ࠧ 뢠
 RESET    ⥭ ॣ ﭨ.
     4-7 ⠭ 直 ࠧ,  ᮮ⢥騩 
訢 㦨.

ͻ
 7  6  5  4  3  2  1  0 
ͼ
                        1 - TC  0
                       
                    	1 - TC  1
                    
                  	1 - TC  2
                 
              		1 - TC  3
              
            1 - 㤮⢮७   0
           
        	1 - 㤮⢮७   1
        
      	1 - 㤮⢮७   2
     
  		1 - 㤮⢮७   3
  

	 . 6.12.  ﭨ

		     ६ ॣ (TR - 00D, 0DA)
		     ---------------------------------
     ᯮ  ࠭   祭 ।
-.	᫥ 砭 । ᫥ ᫮   ⠭
ய஬.
     ᥣ ᮤন ᫥ , ।	 ।饩
樨 -, ᫨  襭  RESET.


    Ŀ
    ணࠬ஢ ஫࠳
     ஫ DMA  ணࠬ஢
஬,  HLDA  ⨢;  ⢥ত ⨭,  ᫨
⨢ HRQ. ⢥⢥  砥  ࠭⨨, 
ணࠬ஢ ஫  ⨢ HLDA ᪫騥.
    ᫨ -CS  HLDA   ﭨ, ஫ DMA 室  ०
ணࠬ஢.  롮 ॣ஢  ணࠬ஢ ⢫ 
 ᭮ 設 A0-A3, ࠡ饩  室,  롮 ०  
뢠 -   ᨣ -IOW  -IOR.	 /뢠 16-
ࠧ來 ॣ஢   稪 ᮮ⢥饣  室
⥫ ࠧ ,  ⢥ ண ᯮ ७
ਣ FF.   FF=0 ந室 饭  襬 ,   FF=1 - 
襬  ॣ   稪.
    ஬ ⮣,  ஫  ⥫ ᯥ樠
,    믮  ० ணࠬ஢  
   ࠧ冷  設 .    ⭮ ᫥騥
:
    1)  ਣ FF (Clear First/Last Flip-Flop; 00C, 0D8).
      믮 ।   ⥭ ଠ樨 
ॣ஢   稪 ᫮ ஫ DMA.  ਣ FF
⠭ ⠪ ࠧ, ⮡ ய ᮢ 訩 
訩   㦭 ᫥⥫쭮;
    2) ⪠ (Master Clear; 00D, 0DA).
     ⮩ ணࠬ   ஫ DMA 믮 ⠪ 
⢨,    ⭮ RESET.   ॣ ,
ﭨ, ᮢ  ਣ FF,  ॣ ᪨ ⠭.  ᫥
⮣ ஫ DMA 室  宫⮩ 横;
    3) c ॣ ᪨ (Clear Mask Register; 00E, 0DC).
     ⮩   ࠧ ᮪   4 , 
ࠧ蠥  ਭ  DMA.
    ᫥ 祭 ⠭ ।,   ७ 祩,
ᮡ ॣ MOD,  㦥  ⢨⥫
祭.   室 ᤥ,  ᫨   
ᯮ.
     室 ᫮  ணࠬ஢  ࠢ ⥬ DMA
ਢ  ⠡. 6.5.

 . 6.5. ᫮  ணࠬ஢  ࠢ ⥬ DMA
Ŀ
FF -IOR-IOW    A3 A2 A1 A0	        	      
Ĵ
 0   1   0  0h 0  0  0  0  .  CAR  BAR  0
 1   1   0  0h 0  0  0  0  .  CAR  BAR  0
 0   0   1  0h 0  0  0  0 ⥭ .  CAR  0      
 1   0   1  0h 0  0  0  0 ⥭ .  CAR  0      
 Ĵ
 0   1   0  1h 0  0  0  1  .  CCR  BCR  0
 1   1   0  1h 0  0  0  1  .  CCR  BCR  0
 0   0   1  1h 0  0  0  1 ⥭ .  CCR  0      
 1   0   1  1h 0  0  0  1 ⥭ .  CCR  0      
 Ĵ
 0   1   0  2h 0  0  1  0  .  CAR  BAR  1
 1   1   0  2h 0  0  1  0  .  CAR  BAR  1
 0   0   1  2h 0  0  1  0 ⥭ .  CAR  1      
 1   0   1  2h 0  0  1  0 ⥭ .  CAR  1      
 Ĵ
 0   1   0  3h 0  0  1  1  .  CCR  BCR  1
 1   1   0  3h 0  0  1  1  .  CCR  BCR  1
 0   0   1  3h 0  0  1  1 ⥭ .  CCR  1      
 1   0   1  3h 0  0  1  1 ⥭ .  CCR  1      
 Ĵ
 0   1   0  4h 0  1  0  0  .  CAR  BAR  2
 1   1   0  4h 0  1  0  0  .  CAR  BAR  2
 0   0   1  4h 0  1  0  0 ⥭ .  CAR  2      
 1   0   1  4h 0  1  0  0 ⥭ .  CAR  2      
 Ĵ
 0   1   0  5h 0  1  0  1  .  CCR  BCR  2
 1   1   0  5h 0  1  0  1  .  CCR  BCR  2
 0   0   1  5h 0  1  0  1 ⥭ .  CCR  2      
 1   0   1  5h 0  1  0  1 ⥭ .  CCR  2      
 Ĵ
 0   1   0  6h 0  1  1  0  .  CAR  BAR  3
 1   1   0  6h 0  1  1  0  .  CAR  BAR  3
 0   0   1  6h 0  1  1  0 ⥭ .  CAR  3      
 1   0   1  6h 0  1  1  0 ⥭ .  CAR  3      
 Ĵ
 0   1   0  7h 0  1  1  1  .  CCR  BCR  3
 1   1   0  7h 0  1  1  1  .  CCR  BCR  3
 0   0   1  7h 0  1  1  1 ⥭ .  CCR  3      
 1   0   1  7h 0  1  1  1 ⥭ .  CCR  3      
Ĵ
 -   0   1  8h 1  0  0  0 ⥭ STAT			      
 -   1   0  8h 1  0  0  0  CR			      
 -   1   0  9h 1  0  0  1  REQ			      
 -   1   0  Ah 1  0  1  0  ⤥ ࠧ冷 MASK     
 -   1   0  Bh 1  0  1  1  MOD			      
 -   1   0  Ch 1  1  0  0  ਣ FF		      
 -   1   0  Dh 1  1  0  1 ⪠			      
 -   0   1  Dh 1  1  0  1 ⥭ TR			      
 -   1   0  Eh 1  1  1  0  MASK			      
 -   1   0  Fh 1  1  1  1    ࠧ MASK	      



    Ŀ
    ਬ ணࠬ஢ ⥬ DMA
     PC AT ᯮ  2
஫ DMA     ᪮. ⮡    ୮
 , 室 㧨 ᮮ⢥騩 ॣ ࠭. 
 砥   2    81h.
     ਢ ਬ ࠭稬 ᬮ७ ⠭  2 
⥭	 ᥪ (512 )  ᪠, 稭  ᬥ饭 
࠭, ᮤঠ饣  BX. ணࠬ  ᫥騩 :

	mov al,46h     ; 2, ।  , ⥭  ᪠
			(4h    )
	out dma+0B,al  ;⠭  ०
	out dma+0C,al  ; ਣ FF
	mov al,bl      ;㧨 ᬥ饭 ᮢ  ⥪騩 ॣ
			࠭ DMA
	out dma+4,al
	mov al,bh
	out dma+4,al
	mov al,0       ;㧨 稪=512
	out dma+5,al
	mov al,2
	out dma+5,al
	out dma+0A,al  ;᪨஢  2   ᥪ

    ਬ砭: dma -   , ࠢ 00h.



       ͻ     ͻ  ͻ			  ͻ 0-3
-EOP<>  	        ६	   ६./६. 			     /\
RESET> ᨭ-     ĺ  ĺ	   0-7	   / \/
  -CS> 樨     ६. ॣ	    ६.  > 뢮 
READY>  -     稪 ᫮ (16)   ॣ  (16)  		    	  ͼ
  CLK>       ͼ  ͼ		    	      
  AEN<ĺ		       		     	  /\  8-15	     
ADSTB<ĺ		       Ĵ	  Ŀ          ͻ 4-7
-MEMR<ĺ	<Ŀ	       Ŀ  	  Ŀ             \
-MEMW<ĺ	  	       		    		          > 뢮 /
-IOR<>	    ͻ     ͻ               	    
-IOW<>	      ⥭	           	               ͼ
       ͼ     		       ⥭/	           
		     ĺ     ĺ           
		     볐     볐       ͻ
		          ⥪饣⥪饣           
		       稪       稪       ࠢ-
		     (4*16)  (4*16)	     (4*16)  (4*16)	            
		     ͼ     Ѽ       -
		   	   	    		    	                    
		   	   	              ͼ
		   	    Ŀ               
		   			     	    	           Ŀ  
		   			     	    	           Ŀ  
		   			     	    	      	     
		   			     	    	      	     
		   			  ͻ ͻ      
		   			   ᨺ  ⥭      
		   			  ͼ ͼ      
       ͻ   ͻ		/\	       /\	     D0-D1
DREQ0>  	   	  /Ŀ 		       	     
DREQ1> -<ĺ (8) \Ŀ 		       	   \/     ͻDB0-DB7
DREQ2> 	    ͼ   \   /\
DREQ3> ਮ-    ͻ   ĿĿĿ/ / \/
 HLDA> ⮢	    	  /ٳ        	      	   	    뢮 
  HRQ<ĺ	<ĺ ᮪ (4) \Ŀ        	      	   	   ͼ
DACK0<ĺ	    ͼ           \/	     \/ 	   \/
DACK1<ĺ	    ͻ    ͻ ͻ ͻ
DACK2<ĺ	     -/ٳ       - ६   
DACK3<ĺ	<ĺᮢ (4) \ ० (4*6) ﭨ (8)   ॣ (8) 
       ͼ    ͼ	ͼ ͼ ͼ



			      . 6.4. -奬 ஫ DMA


