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RE: [pci] HOST bridge with all 6 PCI images



Hello!

AFAIK, it has nothing to do with the number of images implemented,
whether 1,2,6,etc. It all depends on how the bridge is implemented, HOST
or GUEST. If it's implemented as GUEST then the pci target has read and
write ports on the config space while the wishbone slave has only a read
only port. If HOST then it is the other way around; wishbone slave has
both read and write ports while pci target has only a read port.

To aswer your question as to whether the target can read from the config
space when the bridge is implemented as host, the answer is yes as long
as the NO_CFG_IMAGE is not defined(commented out). With this defined,
then the read only access to the config space from the target is
disabled.

Hope this helps!

Radwin

> -----Original Message-----
> From: owner-pci@opencores.org 
> [mailto:owner-pci@opencores.org] On Behalf Of mini_monkey@163.net
> Sent: Wednesday, August 06, 2003 12:35 AM
> To: pci@opencores.org
> Subject: [pci] HOST bridge with all 6 PCI images
> 
> 
> hi :
>    I am reading the pci_design_document.Now a simple question 
> confused me.It is said that If PCI bridge is implemented as 
> HOST bridge 
> with all 6 PCI images (PCI_IMAGE6) , then there is no Read-Only port 
> connection between Configuration space and PCI Target Unit.Dose it  
> mean in that way the pci target can not read the 
> configuration spae? Why this way?Can anybody explain it 
> .Thanks a lot in adavance! 
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