Subject: comments on BIRD 6.1

From: [email-masked] (Syed Huq)
Date: Mon, 31 Jan 94 16:58:41 PST

Hi Bob Ross,
	I have read thru your BIRD 6.1 and have also seen some of the comments
	from other fellow IBIS members. Overall it looks good. 

	One thing I want to be clear about is [Diff_Pin] and inv_pin are for 
	a Differential receivers input pins and in that case vdiff is the 
	peak-to-peak voltage of the receiver inputs.

	vdiff can also be the differential output of a driver. In that case it
	is assiged 0V(differential not ground-just as your note says). 0 volts
	differential shows only the cross over points of the driver outputs.

	I know we only talk about skews but can Differential Prop delay be 
	measured thru the simulators. For example, for the driver this would
	mean the delay from 1.5V(input) to the 0v(differntial output).

	Also, last point, us semiconductor vendors do an extensive characterization
	on each device across Vcc, temp, process corners and package types to 
	gather data. We do not base our simulations on datasheet numbers only.
	Thanks Will for pointing that out too.

	If we create IBIS files, our data will be based on the above mentioned.

Regards,
Syed.