Here is an explanation from book "The Linux Kernel",
http://www.science.unitn.it/~fiorella/guidelinux/tlk/node68.html#SECTION00830000000000000000
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PCI I/O and PCI Memory Addresses
These two address spaces are used by the devices to communicate with
their device drivers running in the Linux kernel on the CPU. For example,
the DECchip 21141 fast ethernet device maps its internal registers into PCI
I/O space. Its Linux device driver then reads and writes those registers to
control the device. Video drivers typically use large amounts of PCI memory
space to contain video information.
Until the PCI system has been set up and the device's access to these
address spaces have been turned on using the Command field in the PCI
Configuration header, nothing can access them. It should be noted that only
the PCI configuration code reads and writes PCI configuration addresses; the
Linux device drivers only read and write PCI I/O and PCI memory addresses.
On Jan 31, 2008 4:20 PM, jeyram jadenthradevan <[EMAIL PROTECTED]> wrote:
> hi,
>
> can anyone tell me what is the different between pci IO and pci memory ?
>
> thanks
>
>
>
