How to recover from a wrong types DCF record in Calypso MPC5746C MCU?

[youssefboughall]

Hi,

This my first post in this community and let's start with a very critical problem.

I tried to disable the MBISt test on MPC5746C, and I read from a file pointed to in the MCU datasheet that I have write a pattern in the next free area in the UTEST area for DCF records. the pattern is : 0x7F000000 0x0008000C.

But due to a mistake a started by writing the pattern : 0XFFFFFFFF 0x7F000000, and then I recovered that by writing the correct pattern after that wrong pattern.

The problem is that the MCU now doesn't want to start up and get stuck in the BAF area, indicating that a self test occurred all the time.

So is there any solution to recover from this ? or to bypass the wrongly written DCF record ?

Thank you very much for your support in advance.

[petervlna]

Hi,

As UTEST flash is OTP there is no way to remove the incorrect record.

However, adding corrected record will fix this issue.

In some cases you can see in SSCM set bit CER or CERS.

"The problem is that the MCU now doesn't want to start up and get stuck in the BAF area, indicating that a self test occurred all the time." - Could you explain this in detail?

Peter

[youssefboughall]

Hello, Peter

Thank you for the response. As a matter of fact, I have already written a correct record, but it didn't work. Moreover, I ve written the whole record already existing in the UTEST area, but it didn't work either.

Coming to your question, When I trace the code running in the ECU, I noticed that it gest stuck in a loop in the BAF area, and when I check the MC_RGM[FES], I indicates always that a self test has occurred, and MC_RGM[DES] indicates always that A power On reset event has occurred, and it gets never cleared.

Thank you.

Best Regards.