• State Resolved
  • Locked Locked
  • Replies 7 replies
  • Subscribers 31 subscribers
  • Views 386 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.

RM48L952: What is the CPU-SelfTest

user4127213
Prodigy 250 points
Part Number: RM48L952


Dear All,

I would like to know what the CPU SelfTest. Is it detect stack overflow?  It is happy if you tell me the proper documentation.

Regards,

SONE

  • 0
    Prodigy 250 points

    Dear All,

    I have one more question. Could you tell me what  the MMU/MPU is ?

    How can I tell the MMU/MPU is activated ? Which .c code should I see?

    Regards,

    SONE

  • 0 in reply to user4127213
    TI__Guru**** 199096 points

    Hello Sone,

    MMU is memory management unit. MPU is memory protection unit. RM48 devices has built-in 12 regions MPU, but the MMU is not implemented in this device.

    The MPU is not enabled at reset. Software must enable, configure and test the MPU. The MPU enables you to partition memory into regions and set individual protection attributes for each region. So the MPU logic can be used to provide spatial separation of software tasks in the device memory. The MPU can also be used to configure the memory ordering policies of the memory system.

    Please refer to MPU chapter in ARM Cortex-R4F TRM.

  • 0 in reply to QJ Wang
    TI__Guru**** 199096 points

    The CPU selftest is to test the HW logic inside the chip using LBIST mechanism. It doesn't detect the stack overflow.

  • 0 in reply to QJ Wang
    Prodigy 250 points

    Hi, QJ Wang,

    Thank you for teaching. Are there any mechanism which could check the stack overflow ?

    I also would like to know ragarding SYSESR resister.  Could you tell me who and when the bit in the SYSESR resister set ?

    Regards,

    SONE

  • 0 in reply to user4127213
    TI__Guru**** 199096 points

    Hello Sone,

    If your code runs out of stack space, or a task runs out of it’s allocated stack space, a stack overflow occurs. The very common examples are:

    1. Have large arrays in your code

    2. To much recursion in functions call. Every time a function in entered, a stack frame is created and placed on the stack. Recursively enter a function too many times, and the stack frames may fill up the task stack to the point of overflow.

    There is no dedicated hw mechanism to detect the stack overflow. You can check the stack usage in your code debug time. The CCS has a built-in feature to check the stack usage: CCS-->View--> Stack Usage.

  • 0 in reply to QJ Wang
    TI__Guru**** 199096 points

    The SYSESR (system exception status register) indicates the source for different reset encountered. 

    Please refer to Table 2-8 (Causes of Resets) in TRM for details

  • 0 in reply to QJ Wang
    Prodigy 250 points

    Hi, QJ Wang,

    I understand that. Thank you.  I will check stack usage with CCS. 

    Best Regards,

    Sone