MK60DN512ZVLQ10 4N30D Reset Problem

[GottiLuca]

We've done a custom board with MK60DN512ZVLQ10  ( 144 pin LQFP version ), mask set 4N30D installed.

Mask set 4N30D should be the INITIAL production mask set , so really close to the definitive one ...

However, we've seen a problem when powering the 3,3 V supply with a ramp time less of 2 ms ( something that could happen for example if u're using the micro for a USB device , but not only in this case ) : the microcontroller simply doesn't reset itself  .

We've also tried to add an external reset generator ( like MAX809 ) but nothing : if 3,3 V supply is too "fast" the micro doesn't start. The polite thing is that if we , after power up event ( even 2 ms after ) , reset the part by an external reset switch, the

part starts.

After struggling our minds for some days with this problem, at the end we've tried to install the very same pcb a PK60N512VLQ10 with mask code 0M33Z ( the initial mask set !!! ) and , magically, problem disappeared !!!

So, our conclusion is that on mask set 4N30D there is this very annoying problem !!!

( probably the problem it is related to the POR module and / or reset logic )

[GottiLuca · Accepted solution]

Freescale Italy confirmed us that Freescale has found too this problem on 4N30D mask set and it will be corrected.

Revised errata sheet of the 4N30D will be realised in the following days .

[GottiLuca]

After further investigation, it appears that my REAL problem was caused by a sporious NMI interrupt triggered before system init.

To confirm that we've done a very simple test : we've connected the NMI pin directly to Vdd and problem disappears .