American Megatrends 64 Series, Руководство пользователя

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Chapter 1 - System Overview 6
Description,
Continued
Seven DMA Channels
The Baby EISA motherboard has seven DMA channels. Any DMA channel may be
programmed for 8, 16, or 32-bit DMA device size and ISA compatible, type
A, type B, or burst modes.
Fifteen Interrupt Levels
The motherboard has 15 hardware interrupt levels. The NMI takes
precedence over hardware interrupts.
Priority Label Typical Interrupt Source
1 IRQ 0 Interval Timer 1, Counter 0 OUT
2 IRQ 1 Keyboard
3 – 10 IRQ 2 Used internally for IRQ 8 through IRQ 15
3 IRQ 8 Real-TIme-Clock
4 IRQ 9 EISA bus
5 IRQ 10 EISA bus
6 IRQ 11 EISA bus
7 IRQ 12 Mouse on EISA bus
8 IRQ 13 Coprocessor Error
9 IRQ 14 EISA bus (Hard disk drive controller)
10 IRQ 15 EISA bus
11 IRQ 3 EISA bus (Serial Port 2)
12 IRQ 4 EISA bus (Serial Port 1)
13 IRQ 5 EISA bus (Parallel Port 2)
14 IRQ 6 EISA bus and floppy disk controller
15 IRQ 7 EISA bus (Parallel Port 1)
Timer Features
The Baby EISA motherboard has five programmable 16-bit counter/timers.
System Arbiter
The Baby EISA motherboard has standard EISA arbitration features.