, , IBM-PC- . , . x86 , - . DMA, , BIOS () IBM PC.
PC (), . A0000h-FFFFFh Upper Memory Area (UMA), 384 , IBM PC . UMA (E)ISA (, ) (BIOS ). UM. ROM BIOS.
BIOS ROM BIOS E0000h-FFFFFh F0000h-0FFFFFh. , BIOS , 86 (FFFF0h 8086/88, FFFFF0h 80286 386SX, FFFFFFF0h 386DX 32- , FFFFFFFF0h P6 36- ).
-286 386SX 24- FDFFFFh ( 15,9 ). FE0000h-FFFFFFh ROM BIOS, ROM BIOS 0E0000h-0FFFFFh.
386DX 32- 4 , BIOS FFFE0000h-FFFFFFFFh. P6+ 36- 64 BIOS FFFFE0000h-FFFFFFFFFh.
, ROM BIOS, (E)ISA PCI (AGP).
, ISA, UMA A0000h-EFFFFh A0000h-DFFFFh ( ROM BIOS). BIOS (. . 12.7.1). ISA FE0000h-FFFFFFh, ( ) . ISA ( ) CMOS Setup Memory Hole At 15-16, 15 .
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ISA 24- , (ISA Bus Master) ( ) 16 (000000-FFFFFFh). To DMA, ISA ( ).
PCI 32- , [5]. PCI , , ROM BIOS ISA. , PCI, . PCI .
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- IBM PC, 86, . , 32-, - 16- ( 0-FFFFh). PC 16 10 (0-9), 0-3FFL , , . , 378h, 778h, B78h F78h, . , , , ISA . ISA, Legacy Card ( ), . 12- ISA, 10- . MCA PCI 16 . - PC . 12.1. 10- . , , , .
12.1. -
AT PS/2 | PC/XT | |
000-00F | 000-00F | DMA #1 8237 |
010-01F | PS/2 DMA#1 | |
020-021 | 020-021 | #1 8259A |
040-05F | 040-043 | (PC/XT: 8253, AT: 8254) |
060 | 060 | POST ( ) |
060-063 | 8255 | |
060, 064 | AT 8042 | |
061 | NMI | |
070-07F | CMOS NMI | |
080 | ||
080-08F | 080-083 | DMA |
090-097 | PS/2 , | |
00 | NMI | |
0A0-0BF | #2 8259A | |
0C0-0DF | DMA #2 8237A-5 | |
0F0-0FF | 80287 | |
100-1EF | PS/2 | |
170-177 | #2 (IDE#2) | |
1F0-1F7 | #1 (IDE#1) | |
200-207 | 200-20F | |
210-217 | ||
238-23F | COM4 | |
278-27F | 278-27F | LPT2 (LPT3 MDA) |
2A2-2A3 | MSM48321RS | |
2C0-2DF | 2C0-2DF | EGA #2 |
2E0-2E7 | COM4 | |
2E8-2EF | COM4 | |
2F8-2FF | 2F8-2FF | COM2 |
300-31F | ||
320-32F | XT | |
338-33F | COM3 | |
370-377 | #2 | |
376-377 | IDE#2 | |
378-37F | 378-37F | LPT1 (LPT2 MDA) |
380-38F | 380-38F | SDLC/BSC #2 |
3A0-3AF | 3A0-3A9 | BSC#1 |
3B0-3BB | 3B0-3BB | (MDA) |
3B4-3C9 | PS/2 | |
3BC-3BF | 3BC-3BF | LPT1 MDA |
3C0-3CF | 3C0-3CF | EGA#1 |
3C0-3DF | 3C0-3DF | VGA |
3D0-3DF | 3D0-3DF | CGA/EGA |
3E0-3E7 | COM3 | |
3E8-3EF | COM3 | |
3F0-3F7 | 3F0-3F7 | #1 |
3F6-3F7 | IDE#1 | |
3F8-3FF | 3F8-3FF | COM1 |
, , , , . ( ) . 0h-0FFh . ( ) . (ISA, PCI) BIOS .
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, . 86 [6, 7]. , .
(NMI) ( NMI ); 2. PC . NMI , ISA (IOCHK) PCI (SERR#). NMI 1 7 070h, 061h:
♦ 2 R/W ERP SERR# PCI;
♦ 3 R/W EIC ISA;
♦ 6 R IOCHK ISA ( IOCHK#);
♦ 7 R PCK SERR# PCI.
IF ( LI , STI ). , , () , . , , , . , . , IF, . ( IRET) , IF, . ( ), STI. ; STI , ( ) . EOI (End Of Interrupt).
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. , 8259A. . AT . 8259#1 0, 1, 37; . 2 8259#2, 8-15. 8-15 1 3 , . XT , 8259 8 .
i8259A [1, 7]; , . 20-21h (8259A#1) A0-A1h (8259A#2), -. ( POST ) ( ), IRET. . , ( 21h 8259#1, A1h 8259#2), (. . 12.2) . ( ) . EOI (End Of Interruption), :
♦ 1- 20h 20h;
♦ 2- 20h A0h (EOI ), 20h 20h (EOI ).
12.2. ( )
(¹) | / | ||
NMI | 02h | , ( XT ) | |
IRQ0 | 08h | #1/1h | ( 0 8253/8254) |
IRQ1 | 09h | #1/2h | |
IRQ2 | 0Ah | #1/4h | XT , AT ( IRQ8-IRQ15) |
IRQ8 | 70h | #2/1h | CMOS RTC |
IRQ9 | 71h | #2/2h | |
IRQ10 | 72h | #2/4h | |
IRQ11 | 73h | #2/8h | |
IRQ12 | 74h | #2/10h | PS/2-Mouse () |
IRQ 13 | 75h | #2/20h | |
IRQ14 | 76h | #2/40h | HDC |
IRQ15 | 77h | #2/80h | |
IRQ3 | 0Bh | #1/4h | COM2, COM4 |
IRQ4 | 0Ch | #1/10h | COM1, COM3 |
IRQ5 | 0Dh | #1/20h | XT HDC, AT LPT2, Sound () |
IRQ6 | 0Eh | #1/40h | FDC |
IRQ7 | 0Fh | #1/80h | LPT1 |
¹ 0, 1, 8 13 .
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. , . , ( ).
(, , CMOS-, ), . , , ISA/EISA. IRQx (. 12.2). PCI. . , , . .
PCI 4 , INTR , , , D. , ( ). IRQx . IRQx, PCI, ISA. , CMOS Setup, PnP. ISA Legacy IRQx ISA ( ), a PCI/PnP PCI PnP ISA ( ). . 12.1.
. 12.1.
, , . : -, , , ( ). -, , , . PnP ISA PCI, CMOS Setup.
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♦ (level sensitive) , ( ISA ) DRQx. ( EOI ) DRQx, .
♦ (edge sensitive) , ( ISA ) DRQx. , .
IRQx , , . , (spurious interrupt), (IRQ7 IRQ15 ). , .
ISA . : , -, , , -, (. ), . (Level) (Edge) , ISA .
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, , 8259A. 8259A. , POST, . , . Pentium APIC (Advanced Programmable Interruption Controller). APIC, , APIC. 8259A.