Re: pci compliant devices?

[Stuart Adams <sja@brightstareng.com>]

> But this is only a difference in how you use, or look at, the driven
> outputs.
> 
> There is nothing preventing you from designing one CMOS output, and
> measuring it with different test loads and/or voltage levels.

 But the difference between incident and reflected wave signaling is 
 a function of the driver, correct ???

 From the PCI 2.1 spec section 4.1.2:

  "... PCI is based on reflected wave rather than incident wave signaling. 
   This means that bus drivers are sized to only switch the bus half way
   to the required high or low voltage. ..."

 What I am trying to understand is say I have a CPLD with a one size
 fits all (PCI, TTL, etc. compliant) output driver. It's CLK->Q spec 
 guarantees that the outputs will be driven all the way to the 
 rail within 15 ns. Now will this device meet the PCI setup requirements of 7 ns
 in spite of the fact that it does not meet the PCI spec for CLK->Q requirement
 of 11 ns ??? It should since it is not relying on the 10 ns reflected wave 
 prop time in order to reach the required high or low voltage.

-- Stuart