MPC5775 how to get BIST offline test result

[MarkFan]

Hi everyone.

How to get  BIST offline test result after system run?

I tried to access the STCU2 register after MPU initial, reference code  as below 

STCU2_Type * base = STCU2;

ERR_Result = base->ERR_STAT;

However, it will cause system reset when I read STCU2 register.

I don't know why? other MCU registers are OK to access.

Thanks for any help.

Mark

[MarkFan]

Hi Peter,      

   As your suggestion, Just direct read registers from memory however, it still cause system reset. 

uint32_t * stcu_adds = 0xC3FF4000;

Offline_LBIST_Result = *(stcu_adds);

 I tried other address like 0xC3F8_0000 for FCCU is OK.  

It is very strange, any ideas what cause this?

BTW, I cannot find any RGM key word in my MPC5775 datasheet, could you tell me in which registers?

Best regards,

Mark

[petervlna]

Hello,

I am just reading STCU registers via debugger with no issues. I have no SW in micro and JTAG as master accessing registers via core is able to read.

As your suggestion, Just direct read registers from memory however, it still cause system reset.

You can read reset source from SIU_RSR

It is very strange, any ideas what cause this?

No, I am not familiar with your SW. But there are no restrictions for reading STCU results.

BTW, I cannot find any RGM key word in my MPC5775 datasheet, could you tell me in which registers?

Sorry, this device does not have RGM (it has SIU instead). Different architecture.

Best regards,

Peter

[MarkFan]

Hi Peter,

    Thanks for your help. I found the issue but I don't know hoe to fix it. The clock of STCU0_CLK is 0 Hz even I enabled it the component inspector page.

 CRC0_CLK has same problem. When I tried to access the register It will caused system reset. 

 Reset is from FCCU (FCCUURS). How to turn on the sys clock for STCU. 

Best regards,

Mark

[petervlna]

Hello,

The clock of STCU0_CLK is 0 Hz even I enabled it the component inspector page

I am not familiar with these configuration tools. But I do know very well how STCU works on system level.

What you are writing is not correct. STCU clock is active even during reset phase (as STCU performs BISTs and writes the results to the STCU registers). So reading results is possible right after reset is released by any requesting master.

How to turn on the sys clock for STCU.

It is on, by default. In fact you are configuring it in your DCFs.

I have attached for reference DCF programming script with setting to execute offline BIST at 50MHz.

Reset is from FCCU (FCCUURS). How to turn on the sys clock for STCU.

Then read FCCU result registers (NCFSx) to see reset source.

Best regards,

Peter

[MarkFan]

Hi Peter,

    I enable the STCU clock and regenerate Processor Expert code again then success to run online BIST.

however, I checked  my offline BIST result  : STCU->LBS , MBSL value is all 0.

How can I check  offline BIST has run or not ? maybe some thing wrong with my DCF recode?

Thanks for your help.

Best regards,

Mark

[petervlna]

Hello,

To read STCU registers is not needed anything special. There is no protection applied by default and you can read them in user mode with no restrictions.

To see what caused your system reset you can read RGM DES/FES registers.

You can freely read results in debugger if you want.

I guess this is more SW issue on your side. Erase micro and read results, there will be no issue.

Best regards,

Peter