  IRQ, DMA, ̽ ּҿ  ȳ

  : Eugene Blanchard
   <mailto:blanchas@cadvision.com>
  March 1999 Linux Gazette 38
  : 
   <mailto:bschang@kldp.org>
  2000 6 5

  IBM ȣȯ  ǻ͵  IRQ, DMA, ̽ ּ ( Ʈ:
  IOPorts)   ̴.  ȣȯ  ǻͿ ֺ 
   дٰ     ִ ڿ   
  ,  ڿ    ü   ʴ 
  Ϲ̴.    ̷      ϵ ԰
  ÿ IRQ, DMA, ̽ ּ     ؿ   
  ִٸ ϴ   ٷ̴.

  1.  IRQ - ͷƮ Ʈ

  IRQ ͷƮ Ʈ (Interrupt ReQuest) ̴.  [ͷƮ
  Ʈ -α׷ ߴ û].  ̰ ISA Կ Ǿ ִ ֺ
  ⳪ ī尡 CPU ΰ     ġ CPU " 
  ļ Ǹ  "   Ѵ  (EISA MCA Կ 
   Ѵ).  ֺ    ڸ, , Ʈũ ī,
   ī, Ŀ  ī, ϵ ̺ Ʈѷ, ÷
  ̺ Ʈѷ, COM Ʈ  Ʈ  ִ.

  IRQ ϵ ͷƮε,   Ӵ忡 ISA 
  Ǵ  ( -δ  ȸμ)  ϰ
  ִٴ ̱⵵ ϴ.  ISA Կ 8 Ʈ 16 Ʈ   ִ.
  16 Ʈ  ⺻ 8 Ʈ Կ 16 Ʈ   (Extension
  slot)  Ǿ ִ ̴.

  8 Ʈ Կ   IRQ (IRQ0 - IRQ7)  () ϳ 
  ǵ Ǿ ִ.  16 Ʈ Կ뿡  ٸ   IRQ (IRQ8
  - IRQ15) ϳ ߰ ٰ ȴ.  ׷Ƿ ISA   PC
      IRQ Ѵ.  IRQ0 (ͷƮ) 켱 
  ϸ, IRQ7   켱  ִ.  IRQ8 IRQ15
   "Ư" 켱 ִ.

  IRQ8 15 IBM AT ǻ͸   ó Ұ ̴.  
  ÿ  ִ 8 Ʈ XT (8088) ǻͿ AT (286) ǻͿ
  ȣȯ ϱ ؼ,   ο IRQ 켱 "̱" 
   ϳ   ͷƮ Ʈѷ  ؼ .
  ̷ , IRQ8 15  IRQ2  켱  ȴ.
  ⿡ 켱̶ ϴ    ͷƮ ÿ ۵Ǿ ,
   켱    ó Ѵ.

  ߿ : IRQ ǰ ִ (Active) ̽   
  Ǿ Ѵ.      ̽ ϳ IRQ ϰ ִ
  쿡 ̷ Ȳ øƮ Ͼٰ Ѵ.     ǰ
  ִ  IRQ  ()   쿡 CPU    ̽
  " ؾ ϴ "   ̴.   ̹ IRQ5  
  ϰ ְ, Ʈũ ī尡  IRQ5 ϰ ִ Ȳ 
   .     CPU  ־ ϴ   
  ̰ IRQ5 ѿ ̴.   CPU     ؾ ,
  ƴϸ NIC  ؾ    .   Ȳ ǻʹ
   ų ƴϸ ƹ ϵ ƴ    ִ.

  ***IRQ 浹 PC   ߻Ǵ ̴. ***

  Ʒ Ϲ  IRQ   Ҵ.  켱  IRQ
    ̴.  (  IRQ  () ī  ٰ
       ̶...)
  IRQ                                ἱ ()     ISA 
  ------------------------------------------------------------
  IRQ0   System Timer                     No               -
          ý Ÿ̸                     

  IRQ1   Keyboard Controller              No               -
          Ű                            

  IRQ2   Cascaded to IRQ8-15              No               -
          IRQ8-15                 

  IRQ8   Real-time clock                  No               -
          ð                              

  IRQ9   *-Available(IRQ2)                Yes              8/16 Ʈ
          *-  (IRQ2)                 

  IRQ10  NIC                              Yes              16 Ʈ
          Ʈũ ī                    

  IRQ11  SCSI adapter                     Yes              16 Ʈ
          Ŀ  ī               

  IRQ12  Motherboard mouse/available      Yes              16 Ʈ
          Ӵ 콺 /          

  IRQ13  Math coprocessor                 No               -
          ε                        

  IRQ14  Primary IDE controller           Yes              16 Ʈ
          ù ° IDE Ʈѷ             

  IRQ15  Secondary IDE controller         Yes              16 Ʈ
           ° IDE Ʈѷ             

  IRQ3   Com2/Com4                        Yes               8 Ʈ
          COM2 / Com4                      

  IRQ4   Com1/Com3                        Yes               8 Ʈ
          COM1 / Com3                      

  IRQ5   Sound card/LPT2                  Yes               8 Ʈ
           ī / LPT2               

  IRQ6   Floppy drive controller          Yes               8 Ʈ
          ÷ ̺ Ʈѷ         

  IRQ7   Parallel port LPT1               Yes               8 Ʈ
          з Ʈ LPT1                 

  *- IRQ9 ġ IRQ2 ó δ.  ̴  ߻ϴ  찡
     ʴ 찡 .  ¥ IRQ9ΰ? ƴϸ IRQ2
  IRQ9   (Cascade) ΰ?   Ȳ  ߾  ΰ?
   16 Ʈ  ISA Կ 8 Ʈ ISA   Ѵٸ?   
    ִ Ȳ Ǵ ̴.

   ǥ  IRQ     ǵ  
  ̴.  μ  Ŀ  ʴ Ȳ̶ IRQ11
  ڸ Ǵϱ ٸ Ʈũ ī峪 ٸ ̽   
  ̴.

  κ ڵ ν ϴ Ʈ    ü IRQ
    ߾ ֱ⸦  ̴.

  2.  COM Port Conflicts

  켱    (PC ڿ ִ DB9 Ʈ ) COM1 COM3 IRQ4
  Ѵٴ ̴.      ϳ ̽ Ǵ  ٸ
  ̽ ͷƮ   ʴ  쿡   Ѵ.  
  COM1 콺 ؼ ϴ 쿡  COM3 Ἥ   
  ϴ   ȵȴٴ ̴.   ״  øƮ
  ߻ȴ.    Ǯ ׸ ̷   ֱ⵵ ,
  κ  ׳ ׾ ų     ʴ Ȳ
  ǰ ȴ.   콺 ̸  α׷  ڸ
  ޾ƿ  찡  ̴.

  (PC  DB25 Ʈ ) COM2 COM4    ,
  κ  COM4  ʴ´.  Ϲ COM2 
  ؼ  찡 .   COM4 Ǵ 쿡 
  ̳ ÷Ϳ Ǵ 찡 .  Ϲ (COM2 COM4) 
   ÿ Ǵ  .

  Ϲ  Ʈ 

  Ʈ  IRQ     
  -------------------------------------------
  COM1  4       콺
  COM2  3       ÷ /   /  
  COM3  4         (콺 浹)
  COM4  3         /  

  3.  DMA - Ʈ ޸ 

  DMA Direct Memory Access ̴.    ̽ CPU
  ġ ʰ  ޸𸮸 а   ִ   ̰ ִ.  
    CPU  ۾       ִ 
  Ѵ.

  PC DMA0 DMA7   DMA ä ִ.  ̴ 8 Ʈ ISA
  ԰ 16 Ʈ ISA Կ  8 Ʈ äΰ 16 Ʈ äη 
  .

  DMA ä    ǵ   Ҵ.

  DMA                        ()         ISA         ä 
  ----------------------------------------------------------------
  DMA0 Available                           16 Ʈ          8 Ʈ
          ڸ

  DMA1 Sound                                8 Ʈ          8 Ʈ
          

  DMA2 Floppy Disk controller               8 Ʈ          8 Ʈ
          ÷ ũ Ʈѷ

  DMA3 ECP Parallel Port                    8 Ʈ          8 Ʈ
          ECP з Ʈ

  DMA4 * - Not used                 -              16 Ʈ
          *-  

  DMA5 Sound                               16 Ʈ         16 Ʈ
          

  DMA6 SCSI                                16 Ʈ         16 Ʈ
          Ŀ

  DMA7 Available                           16 Ʈ         16 Ʈ
          ڸ

  : DMA0 16 Ʈ ISA  Ǿ   8 Ʈ
  Ұϴ.  DMA4 ù ° 8 Ʈ DMA Ʈѷ   (Cascade)
  Ǿ ֱ      .

  ***DMA 浹 PC ߻Ǵ  °   ̴.  ***

  IRQ , DMA  ǰ ִ ̽  ϳ
  Ǿ Ѵ.  ׷  浹 ߻Ѵ.  忡 Ǹ
    "ǰ ִ" ̶ ̴.    DMA  
  ̽   ,  쿡  ̽ 
  "ǰ ִ" Ȳ̾ Ѵ.

  4.  ̽ ּ

  ̽ ּҴ  I/O Ʈ, I/O ּ, I/O Ʈ ּ, Ǵ ̽
  Ʈ Ҹ.  ̽  Ҵ  ü (ֺ ) I/O
  ̽ ̿ ̽  ִ ޸   ̴.  ֺ
    ̽ ּҸ Ἥ  ü   ϰ ȴ.  (̳
  Ʈ  )  ֺ   ̽ ּҸ  ־
  Ѵ.

  Ϲ ̽ ּ   (h- 16 )
  ------------------------------------------------------
  060h + 064h             Keyboard controller
                          Ű Ʈѷ

  170h + 376h             Secondary IDE Hard-drive controller
                           ° IDE Ʈѷ

  1F0h + 3F6h             Primary IDE Hard-drive controller
                          ù ° IDE Ʈѷ

  220h                    Sound Card
                           ī

  300h                    NIC card
                          Ʈũ ī

  330h                    SCSI adapter
                          Ŀ 

  3F2h                    Floppy Drive Controller
                          ÷ ̺ Ʈѷ

  3F8h                    COM1

  2F8h                    COM2

  3E8h                    COM3

  2E8h                    COM4

  378h                    LPT1

  278h                    LPT2

  ***̽ ּ 浹 PC  °  ߻Ǵ ̴. ***

   ǥ Ǵ ̽ ּ Ϻ  Ұϴ.   Ǵ
  ̽ ּҴ PC   ġǾ ִ   ޶.

  5.   ڿ 

    ִ    /proc 丮  
   캸 ȴ.

  cat  /proc/interrupts             ǰ ִ ͷƮ 
  cat  /proc/ioports                ǰ ִ ioports (̽ ּ) 
  cat  /proc/dma                  ǰ ִ DMA 

  6.   

  ÷-ص-÷ Ͽ ϴٰ   ϰ Ǿϴ.
  Ͽ      Ϳ ϸ   
  ª ִ ״          ϱ
  Ͽϴ.  ƹ    ̰ ڿ ϸ 
  ׷  Ƿ ִ  ƴ,     ̻ϰ
  ǥ κ   ̴ϴ.  ٶϴ.

   ª ŭ ڼ   ʰ ֽϴ.    ڼ
   ϽŴٸ ÷-ص-÷ Ͽ о ðų 
  URL      ֽϴ.    ٸ 
  "Introduction to Data Communications" ø  ſ 
     Ǿ ֽϴ.
  http://www.cadvision.com/blanchas/intro_to_data_com/intro.html
  <http://www.cadvision.com/blanchas/intro_to_data_com/intro.html>

  6.1.    (Acknowledgements)

  o  Eugine Blanchard:     ֽ  í Կ
     帳ϴ.  Thank you very much for giving me a permission to
     translate this wonderful document!

   í ۱  1999.
   Ʈ 38ȣ (1999 3) Ǿ.

  Copyright   1999, Eugene Blanchard
  Published in Issue 38 of Linux Gazette, March 1999

   URL: http://www.linuxgazette.com/issue38/blanchard.html
  <http://www.linuxgazette.com/issue38/blanchard.html>

            Ȩ         :
  http://www.cadvision.com/blanchas/
  <http://www.cadvision.com/blanchas/>

