Re: Hardware verification

Victor Yodaiken (
Wed, 14 Dec 1994 08:56:27 -0700

On Dec 12, 10:46am, David Shepherd wrote:
Subject: Re: Hardware verification
>Victor Yodaiken has said:
>> There is an interesting discussion on this issue in the RISKs forum.
>> Does anyone know what INMOS got wrong in their floating point spec?
>Not sure we had anything wrong with our spec!

In RISKS, Kahan was claimed to have said that INMOS got the spec
wrong -- I have no idea what he meant or whether he would agree with
this report.

>5) The Pentium bug seems to have been caused by "missing entries"
>in a division lookup table. I'm fairly certain that our production
>testing used evaluations that would exercise every entry in our
>division and multiply lookup tables - we caught some yield hazards
>in revB that way (multiply table outputs were not fast enough in
>75% of chips!) - if Intel had used this type of testthen surely

So how much of the verification was testing and how much was mathematical