• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 31 subscribers
  • Views 569 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ALGO Register selecting invalid TEST PATTERN with OVER=0 bit and RINFOL slecting DCAN1 RAM Group

Pashan
Intellectual 715 points

Hello,

In spnu489b.pdf, there is an example of PBIST with No RAM Override [OVER=0] in the section:

 

6.8.1 Example1 : PBIST Configuration for DCAN1 RAM with No RAM Override

In the given example ALGO=0x54, which selects valid TEST PATTERN for DCAN1 RAM.

For the given example, instead if we use ALGO=0xFF, the some invalid TEST PATTERNS will be selected for DCAN1 RAM Group.

Is it an issue or PBIST will only select the valid TEST PATTERNS from the ALGO Register for the particular RAM Group selected through RINFOL Register?

Please let me know how ALGO Register is used by PBIST when OVER=0.

Thank you.

Regards

Pashan

 

  • 0
    TI__Genius 14205 points

    Hi Pashan,

    You can make PBIST to run selected patterns/ALGO on Selected momory or all memories. This is controlled by OVERRIDE register OVER0 bit.

    If you want to run only March13n_red algo on DCAN1 RAM,  RINFOL = 0x4, Select ALGO = 0x4 , make sure OVER = 0.
    If you want to run only March13n_red algo on ALL RAMs,  RINFOL = ( Anything- does not matter), Select ALGO = 0x4 , make sure OVER = 1, PBIST will run the selected Algo/pattern on the applicable RAMs,  You need not worry to select the corresponding RAMS for selected Algo.

    Best Regards
    Prathap

     

     

  • 0 in reply to Prathap
    Intellectual 715 points

    Hello Prathap,

    My question is the opposite one.

    I am asking that if I set ALGO Register's all the BITS to 1, even though some TEST PATTERNS are not valid for the selected RAM for which I have enabled PBIST using RINFOL.

    So, my question is that does PBITS ignores the ALGO Register's INVALID Bits being set to 1 or it doesn't ignore the INVALID Bits and creates ERROR Result.

    In essence, does it matter if I set all bits of ALGO Register to 1 always, independent of RINFOL contents when OVER=0?

    Or, is there some side-effect when I set ALGO = 0xFFFFFFFF.

    Thank you.

    Regards

    Pashan

  • 0 in reply to Pashan
    TI__Genius 13810 points

    If OVER=0, PBISTs will NOT ignore the ALGO register's invalid bits. It will generate PBIST error.

    If OVER=1 (default), PBISTs will ignore the ALGO register's invalid bits.

    Regards,

    Haixiao

  • 0 in reply to Haixiao Weng
    Intellectual 715 points

    Hello Haixiao,

    Does this mean, I cannot include two RAM Groups like DCAN and ROM within RINFOL/RINFOU Registers, when OVER=0?

    Because under that circumstance, ALGO Register contains TRIPLE READ test pattern bits set, which are not valid for DCAN RAM Test Pattern.

    Is the assumption correct, assuming that PBIST checks for INVALID Bits everytime it tries to test any RAM GROUP bit defined MEMORY?

    Please confirm.

    Thank you.

    Regards

    Pashan

     

  • 0 in reply to Pashan
    TI__Genius 13810 points

    Yes, with over=0, you can not test ROM and RAM together.