In the x86 architecture, an input/output base address is the first I/O address of a range of consecutive read/write addresses that a device uses on the x86's I/O bus. This base address is sometimes called an I/O port.
Common I/O base address device assignments in IBM PC compatible computers
This table represents the common I/O address ranges for device assignments in IBM PC compatible computers. The base address is the first in each range. Different types of devices can vary in the number of I/O ports they need for communication with the CPU, therefore the extent of the address range varies. Also, address decoders often do not decode all address bits, causing the necessary I/O address range window to be larger than necessary or mirrored to other addresses as well. Each row of the table represents a device or chip within the computer system. For example, the address of the status port in a parallel printer adapter is at 0x0001. Depending on the adapter's configuration, this may be mapped in at different locations within the PC's I/O address range. Assuming, the adapter would present a third parallel port (with base address 0x0278), this would result in the status port mapped in at 0x0279 in the CPU'S I/O address space.
When there are two or more identical devices in a computer system, each device would be mapped to a different base address (e.g. LPT2 and LPT3 for printers).
input, output, base, address, architecture, input, output, base, address, first, address, range, consecutive, read, write, addresses, that, device, uses, this, base, address, sometimes, called, port, contents, common, base, address, device, assignments, compat. In the x86 architecture an input output base address is the first I O address of a range of consecutive read write addresses that a device uses on the x86 s I O bus This base address is sometimes called an I O port Contents 1 Common I O base address device assignments in IBM PC compatible computers 2 See also 3 References 4 External linksCommon I O base address device assignments in IBM PC compatible computers EditThis table represents the common I O address ranges for device assignments in IBM PC compatible computers The base address is the first in each range Different types of devices can vary in the number of I O ports they need for communication with the CPU therefore the extent of the address range varies Also address decoders often do not decode all address bits causing the necessary I O address range window to be larger than necessary or mirrored to other addresses as well Each row of the table represents a device or chip within the computer system For example the address of the status port in a parallel printer adapter is at 0x0001 Depending on the adapter s configuration this may be mapped in at different locations within the PC s I O address range Assuming the adapter would present a third parallel port with base address 0x0278 this would result in the status port mapped in at 0x0279 in the CPU S I O address space When there are two or more identical devices in a computer system each device would be mapped to a different base address e g LPT2 and LPT3 for printers I O address range Device00 1F First DMA controller 8237 A 520 3F First Programmable interrupt controller 8259A 40 5F Programmable interval timer System Timer 825460 6F Keyboard 804270 7F Real time clock NMI mask80 9F DMA Page Register 74LS61287 DMA Channel 083 DMA Channel 181 DMA Channel 282 DMA Channel 38B DMA Channel 589 DMA Channel 68A DMA Channel 78F RefreshA0 BF Second Programmable interrupt controller 8259A SlaveC0 DF Second DMA controller 8237 A 5F0 Clear 80287 BusyF1 Reset 80287F8 FF Math coprocessor 80287F0 F5 PCjr Disk ControllerF8 FF Reserved for future microprocessor extensions100 10F POS Programmable Option Select PS 2 110 1EF System I O channel140 15F Secondary SCSI host adapter170 177 Secondary Parallel ATA Disk Controller1F0 1F7 Primary Parallel ATA Hard Disk Controller200 20F Game port210 217 Expansion Unit220 233 Sound Blaster and most other sound cards278 27F Parallel port 3280 29F LCD on Wyse 2108 PC SMC Elite default factory setting2B0 2DF Alternate Enhanced Graphics Adapter EGA display control2E8 2EF Serial port 42E1 GPIB IEEE 488 Adapter 02E2 2E3 Data acquisition2F8 2FF Serial port 2300 31F Prototype Card300 31F Novell NE1000 compatible Ethernet network interfaces300 31F AMD Am7990 Ethernet network interface IRQ 5 320 323 ST 506 and compatible hard disk drive interface330 331 MPU 401 MIDI processing unit on most sound cards340 35F Primary SCSI host adapter370 377 Secondary floppy disk drive controller378 37F Parallel port 2380 38C Secondary Binary Synchronous Data Link Control SDLC adapter388 389 AdLib Music Synthesizer Card3A0 3A9 Primary Binary Synchronous Data Link Control SDLC adapter3B0 3BB Monochrome Display Adapter MDA display control3BC 3BF Parallel port 1 on MDA card3C0 3CF Enhanced Graphics Adapter EGA display control3D0 3DF Color Graphics Adapter CGA 3E8 3EF Serial port 33F0 3F7 Primary floppy disk drive controller Primary IDE controller second I O range 3F6 3F7h 3F8 3FF Serial port 1CF8 CFC PCI configuration spaceNote For many devices listed above the assignments can be changed via jumpers DIP switches or Plug And Play software See also EditIRQ interrupt requestReferences EditHelpPC Quick Reference Utility by David JurgensExternal links EditRalf Brown s Interrupt List includes a list of I O ports on IBM PC compatibles Base address term definition from Webopedia Archived 2009 12 08 at the Wayback Machine Introduction to IRQs DMAs and Base Addresses Copyright c 1999 Eugene Blanchard Published in Issue 38 of Linux Gazette March 1999 The PC Guide Apogee FAQ at RinkWorks Programming the AdLib Sound Blaster FM Music Chips Perangkat Input dan Output Komputer at OS 2 Site tehdian This computing article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Input output base address amp oldid 1148034817, wikipedia, wiki, book, books, library,
