Letters and numbers on processors... what do they stand for?

[doctorq]

Hi,

I just looked at my Blizzard 1260 card produced by DCE. My cpu has several numbers and letters on it, and I was wondering what they meant.

It says XC68060RC50 and on the next line it says 9942. Well, I know what the 68060 and the 50 stands for, but what about the rest?

[GPT]

Phw, I hope no one saw that, mo-o-O-O-HA-HA-HA

Thanks to the "edit" button I now may  rest in peace
 knowing the fack that I used it :-D ;-)

Happy X-MAS (did I spell that right it's looks "wrong")

[GPT]

I was total wrong XC stands for "partial quality" MC is for full quality.

The four quality grade:

MC   = Full quality
XC   = Partial quality
PC   = Product engineering
SPAK = Sample pack

And I think that RC "points to the processor speed" next to the Letters.

[doctorq]

Thanks mate.

Do you know if it has any impact on the speed of the cpu?

[Piru]

Do you know if it has any impact on the speed of the cpu?

None.

Also see 68k-chips-faq for further information.

[Castellen]

The "9942" is a date code, it means manufactured on the 42nd week of year 1999.
A lot of IC manufacturers do this, so it's often a good way to tell the manufacturing date of a piece of electronic equipment, given that most parts will be made less than a year before being used in manufactured equipment.

The other numbers printed on there (you didn't quote them) are usually batch numbers used for quality control, and probably revision numbers of the silicon die used, etc.

[doctorq]

The numbers I typed in the first post was the only numbers on my CPU.

But I would never have guessed the 9942 number, so thank you for that.

How come there are different versions (MC/RC) if there isn't any differences in speed etc?

[Castellen]

The rated speed is only one aspect of the device.

The MC/RC define other things about it.
MC means it's a fully released standard production item, as opposed to the XC prerelease(?) and the SC which refers to customised devices.

The RC means it has the MMU and FPU enabled.

When semiconductors are manufactured, it's near impossible to get a 100% perfect success rate.  There are problems with silicon impurities, manufacturing processes, the way the silicon is made, etc.
So after a silicon die is finished, it's fully tested.  If (for example) the silicon in the FPU section has a problem, the FPU is permanently disabled, and the device is sold as a cheaper 68060LC50, meaning the FPU is disabled.

So in actual fact all the RC/EC/LC variants come from the same die, but due to manufacturing faults, they are de-rated and sold accordingly.
The advantage being is that there is cheaper products on the market for customers who may not require FPU/MMU functions, and there is less wasted devices from manufacturing.

[MarkTime]

Hi doctorq,

a letter is a symbol or representation of an alphabetic character, usually representing a sound of speech.

a number is a sort of mathematical object, that represents a unique meaning that can be derived from counting.

<--ok don't slap me, I think everyone has covered the real answer already. :-D

[zipper]

>The RC means it has the MMU and FPU enabled.

RC means it's a full CPU in a ceramic case.