RE: Reading Base Address Registers

[Brooks Lame <Brooks_Lame@mcg.mot.com>]

Uh, how about zeros?  See implementation note in section 3.2.2.
-- Brooks    :\


> -----Original Message-----
> From: Scott C. Karlin [mailto:scott@CS.Princeton.EDU]
> Sent: Friday, 08 January, 1999 14:57
> To: Mailing List Recipients
> Subject: Reading Base Address Registers
> 
> 
> This question deals with section 6.2.5.1 of Rev 2.1 of the PCI Spec.
> 
> According to the spec, "a type 00h predefined header has six DWORD
> locations allocated for Base Address registers starting at offset
> 10h in the Configuration Space."
> 
> It seems clear how to read each base address register and determine
> whether it is for memory or for I/O.
> 
> How does one determine if a location represents a valid base address?
> That is, if a particular device only needs one of the six base
> address registers, what must be put in the remaining five locations
> to indicate that there are no more needed base address registers?
> 
> Thanks,
> Scott
> 
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> Scott C. Karlin                             Princeton University
> Graduate Student                            Department of 
> Computer Science
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