Re: FPU problems

From: Michael Grove <grovem_at_ridgecrest.ca.us>
Date: Wed, 1 Apr 1998 21:45:10 -0800 (PST)

Return-Path: <falcon040-request_at_rand.thn.htu.se>


On Wed, 1 Apr 1998, Michael Grove wrote:

>> the 040:). I am working on a Falcon (C-LAB/PAL) that bombs when the FPU
>> is accessed. The machine dosen't lock up, just haults and exits the
>> software with a screen full of bombs. I have checked the buffer mod,
>> signal/power to the FPU and replaced the PALs. The diagnostics cart only
>> checks to see if an FPU is present, and reports back ok. I tried
>> GEMBENCH, FPUBENCH and NEMBENCH.

>You're not the only one with this problem, I had it as well when I had
>a FPU. For some reason my FPU only worked in 24MHz, and not 16 or 20!
>I solved this simply by feeding the FPU directly with a 50MHz clock,
>this worked fine.

>Unfortunelately I can't remember which pin I fed, I *believe* it was
>pin 11. Geir Øyvind is the one to ask here.

Good memory:)

I tried a 16, 24, 32, 48, 62 Mhz clock feed into the FPU, but still
the same problem. Guess it is time to start reading the map:(.

Mike
Received on on. april 15 1998 - 06:57:00 CEST