Re: Proposed Assembler Commands

On Sat, 30 Apr 2005 14:21:00 -0700, John Larkin wrote:

> On Sat, 30 Apr 2005 20:24:18 GMT, Tim Hubberstey <bogus@xxxxxxxxxxxxx>
> wrote:
>
>>John Larkin wrote:
>>
>>> Most of these are ancient S/360 instructions. But BCF is the opcode
>>> for Branch and Catch Fire.
>>
>>I once worked at a company where old projects had used a processor
>>(don't remember which one) where one of the illegal opcodes would
>>actually cause the processor to go into a lockup mode where it would
>>overheat and char the PCB. The engineers referred to the illegal opcode
>>as the "Catch Fire and Die" instruction.
>
>
> I understand that you can program a Xilinx FPGA to fry itself, if
> there's enough power supply available. Some of the Spartan 2 startup
> power requirements practically guaranteed that enough power *would* be
> available.

Sure. Think of an FPGA as a kabillion copies of a kabillion drivers
driving one wire. Drive a random mix of drivers into the routing array
and the power supply will melt. This is *exactly* why Xilinx doesn't
release their routing/configuration information. Their tools check for
ptoper outputs, so won't let you do something dumb (at least not *this*
dumb).

> Somebody once designed a chip coating material, for high-security
> applications, that allowed a chip to literally explode itself.

Coating? Ecplode? I doubt it. I'm told the government uses thermite, but
it's hardly a "coating" and will hardly "explode". Having worked in
physical security on encryption hardware (commercial stuff only - no
security clearance here), I've heard much of what the spooks and nukes use.

--
Keith
.

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