MPC5777M online MBIST/LBIST

[mclaude]

Hello community!

We are implementing online BIST on MPC5777M with the package given with the application note 5131, but we do not succeed to write in STCU2 registers, even after applying STCU2 security keys for online bist (without doing step by step in the debugger).

By going through DCF records we manage to write in these registers, and offline BIST are well executed.

Do you have any idea of what is missing in the procedure ?

Attached is the main.c used, from the AN5131.

Thanks by advance.

[mclaude]

Hello,

Thank you for your return.

With your configuration I am now able to write in STCU2 registers.

But is there another way to check online BIST results without passing by an endless loop and exiting it manually ?

[petervlna]

Sure,

Simply write the routine which will check the BIST results and if they are fine the proceed with code execution.

Best regards,

Peter

[mclaude]

So it seems the problem does not come from this.

When executing the code, values are well written in STCU2 registers (CFG, LB_CTRLn, LB_MISRRLHSWn, RUNSW)… but even if the RUNSW register is set, tests are not executed ; all read values in registers LB_MISRRL/HSWn are "0x00000000", and the LBESW fields are all at state "LBIST execution not yet completed".

For MBIST same result, MBELSW registers are at state "MBIST execution still ongoing".

I specify that there is no flag raised in the ERR_STAT register.

Do you have any idea of what may be missing in my configuration?

Best regards,

mclaude

[petervlna]

Hello,

Once you start online BIST, the device will loose debugger connection and will reset after Online BIST is done.

Have a look at my example code here.

best regards,

Peter

[mclaude]

Hello,

I tried the same program, but the reset does not occurs. It is supposed to be triggered at end of LBIST 9 but it seems that even the first LBIST is not executed because LB_MISRRL/HSW0 is set to "0x00000000" and does not change. Also LBESW registers are all at state "LBIST execution not yet completed".

I specify that other registers are well setted (such like expected values of LBIST), and RUN register is at "0x00000301".

What did I miss to do?

Best regards

[petervlna]

Hello,

Please run attached code. I just tested it and the BIST was executed as expected.

Best regards,

Peter

[petervlna]

Hello,

from your very brief description I guess you get STCU watchdog (which is guarding time for register access after unlock) expired.

Execute STCU config code at once, and do not step in debugger.

Have a look at my example code. You have to manually skip endless loop as after the online BIST is done the device will reset. This will ensure that BIST wont run in loops).

best regards,

Peter

Peter