Re: Differential inputs and "tdelay"

Michael:

You are correct. The Input model and input portion of the I/O model
would ignore the tdelay_* information. So the example comment
is misleading.

Best Regards,
Bob Ross
Mentor Graphics

"Mirmak, Michael" wrote:
>
> Fellow IBIS-fans,
>
> I have a simple question relating to language used in the 3.2 specification
> to describe differential pins. The parameters "tdelay_typ," "tdelay_min"
> and "tdelay_max" are described as "launch delays." As such, they seem to be
> analogous to pin-to-pin skews on output-only or I/O buffers. However, this
> conflicts with the examples cited in the 3.2 specification, which include
>
> [Diff Pin] inv_pin vdiff tdelay_typ tdelay_min
> tdelay_max
> 3 4 150mV -1ns 0ns
> -2ns | Input or I/O pair
>
> How can a pair of differential inputs have "launch delays?" Is this a
> reference to a max or min mismatch allowed by the device at these pins?
>
> Thanks in advance for any clarity you can lend!
>
> - Michael Mirmak, Intel Corp.
Received on Wed Jun 21 13:19:19 2000