Re: looking for Parity signal status

[Kevin Normoyle <Kevin.Normoyle@Eng.Sun.COM>]

Nimit: You're not allowed to change C/BE during
wait states caused by irdy/trdy. 

Some pci parts have done this and caused parity errors, 
notably thru bus bridges or any part that sample the C/BE only 
during the first cycle of a stalled data beat.

Do people agree?

-kevin

> I am working on the Parity Block of a PCI COre.
> 
> I am facing problem in deciding what should be the status of PAR,ie, 
> 
> a)last parity should continue ,or
> b)the PAR signal shoul be tristated, or 
> c)a new parity be generated 
> 
> when C/BE has changed but the old Data continues due to wait state
> inserted by 
> i)the initiator during a write transaction ,or
> ii)by the target during a read transaction ,or
> iii)by both at the same time
> 
> Thanks,
> Nimit