RE: Multi-function support in PCI

["Termathe, Gerd" <Gerd.Termathe@fujitsu-siemens.com>]

Hello,

 

I think you will find answers to most of your questions in chapter

3.2.2.3.4. "Selection of a Device’s Configuration Space" (PCI-Spec 2.2).

The system has to scan all multi-function devices to know which functions

are implemented, the devices must respond only to implemented functions

of which function #0 is mandatory.

 

Regards

Gerd Termathe

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Gerd Termathe
Senior Design Engineer
ASIC & IP Design Center
FSC PO PC SB RD 4

Tel.:   +49 821 804-4058
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mailto:gerd.termathe@fujitsu-siemens.com
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-----Ursprüngliche Nachricht-----
Von: Madhura Bokil [mailto:madhura@controlnet.co.in]
Gesendet: Dienstag, 14. November 2000 11:43
An: pci-sig@znyx.com
Betreff: Multi-function support in PCI

Hello,

 

    In case of PCI, I am having some doubts for supporting multiple functions.

    The multiple function is enabled by setting bit 7 in Header Type field of configuration space.

    Each function should have seperate configuration space.

    At a time 8 functions can be supported at the max.

    Now the doubt is:

        How the system comes to know how many functions are supported by the device?

        If the Bit 7 in Header type of first fuction is 1 but that of other functions is 0 or otherwise,

        how all the functions can be assecced?

        If the device is supporting only 3 functions, whether the BIOS will run the configuration cycles assuming

        that the device is supporting 8 functions or it knows where to stop for programming the base address registers.

 

***** Madhura Bokil. *****
ControlNet (I) Pvt. Ltd;
Project Engineer,
Verna - Goa
Goa - 403 722.
Ph. 0832-783615