apps/doc/kinfocenter/ioports/index.docbook

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   8 <article lang="&language;">
   9 <title>I/O Port</title>
  10 <articleinfo>
  11
  12 <authorgroup>
  13 <author>&Matthias.Hoelzer-Kluepfel;</author>
  14 <author>&Helge.Deller;</author>
  15 <author>&Duncan.Haldane;</author>
  16 <author>&Mike.McBride;</author>
  17
  18 <!-- TRANS:ROLES_OF_TRANSLATORS -->
  19 </authorgroup>
  20
  21 <date>2002-02-12</date>
  22 <releaseinfo>3.00.00</releaseinfo>
  23
  24 <keywordset>
  25 <keyword>KDE</keyword>
  26 <keyword>KControl</keyword>
  27 <keyword>ioports</keyword>
  28 <keyword>system information</keyword>
  29 </keywordset>
  30 </articleinfo>
  31
  32 <sect1>
  33 <title>Input/Output Port Information</title>
  34
  35 <para>This page displays information about the I/O ports.</para>
  36
  37 <para>I/O Ports are memory addresses used by the processor for direct
  38 communication with a device that has sent an
  39 interrupt signal to the processor.</para>
  40
  41 <para>The exchange of commands or data between the processor and the device
  42 takes place through the I/O port address of the device, which is a
  43  hexadecimal
  44 number.  No two devices can share the same I/O port.  Many devices use
  45  multiple
  46 I/O port addresses, which are expressed as a range of hexadecimal
  47 numbers. </para>
  48
  49 <note><para>The exact information displayed is system-dependent. On some
  50 systems, I/O port information can not yet be displayed.</para></note>
  51
  52 <para>On &Linux;, this information is read from <filename
  53 class="devicefile">/proc/ioports</filename> which is only available if
  54 the <filename class="devicefile">/proc</filename> pseudo-filesystem is
  55 compiled into the kernel.  A list of all currently-registered I/O port
  56 regions that are in use is shown.</para>
  57
  58 <para>The first column is the I/O port (or the range of I/O ports), the
  59 second column identifies the device that uses these I/O ports.</para>
  60
  61 <para>The user cannot modify any settings on this page.</para>
  62
  63 </sect1>
  64 </article>