XTAL option not working with M908Q4ACE mask ZRRD0550

[tonyp]

Subject says it all.

We have confirmed this problem with all such chips we have in stock. Verified by using the same code with other masks on same PCB but without problems.

There are no errata describing this problem so, does anyone know (by experience I guess) what could be wrong and if it is solvable via software changes only?

TIA

[bigmac]

Hello,

Are you referring to QT4A or QY4A devices?  If the original code was developed for the non-suffix devices, the A-suffix device would require modified code to select the external crystal because the method of selecting the oscillator type is different.  For the original devices, the oscillator type was determined by CONFIG2 setting, whereas for the A-suffix, OSCSC (formerly OSCSTAT) is used.

I wonder if this might be the problem.

Regards,

Mac

[tonyp]

I downloaded the QY4A datasheet and seems that bigmac is correct.  We ordered QT4 parts and apparently received QT4A (I'll have a nice chat about this with my supplier, also), as our part number seems closer to the QT4A part numbers than it is to the QT4 ones.  As for the code being a mask or some other code, I wouldn't know but that's all there is visibly printed on the chip.

I'll go through the recommended/required code changes mentioned in the QY4A datasheet and see if that solves our problems.  But I have a pretty good feeling it will.  I will let know if we still have problems.

Thank you much.

[peg]

Hi Alban,

This family of devices, at least more recently, seems only to have the mysterious secret code and date code printed on them. The mask code IS NOT THERE!

Many have complained about this in the past and requested some kind of cross-reference or something, but nothing seems to be forth-coming.

Tony, I think it is a fair bet this is your problem!

[Alban]

Hello Peg,

Yep, the Mask Set is not displayed.

The info displayed is called Date Code. It shows where is was fabricated: ZR, where is was assembled (put from die into the package): RD and then the date 0550 = 50th week of 2005.

This code is definitely useless to us users, 100% agree with you.

This code is critical for Quality to determine which part is failing and fix/contain/find any fault on a specific device. A quality problem could come from a bad assembly and the mask is not sufficient.

As a user, I would put a Service Request to quality each time I want to know the mask set to apply the device Errata Sheet.

This way, they will see how important it is.

Otherwise, there is NO WAY for a customer to link Errata Sheet to devices they have !

This doesn't mean I won't report it

Thanks Peg,

Alban.

[Alban]

Hello,

Here is an update on this lack of mask info.

A discussion is currently in progress to see how Freescale can easily make the mask set available to all customers on this family.

The trace code has to figure on the device because it is the way to find exactly the whole life of the MCU, whereas the mask set is just telling one of the base material used for the production.

The investigation is progressing with several ideas being brought up and their feasibility being evaluated.

Cheers,

Alban.

[Alban]

Good Afternoon,

The number you gave is not a mask, but the fabrication trace code.

If you have verified that your external oscillator is properly designed and cannot be blamed, you should enter a Service Request as a Quality problem.

To enter a SR, follow the link in my signature below.

Do mention both markings in the SR, so Quality can investigate.

Regards,

Alban.