• State Not Answered
  • Locked Locked
  • Replies 8 replies
  • Subscribers 349 subscribers
  • Views 5303 views
  • Users 0 members are here
2025 survey

We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.

Options
Related
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Continue the Target using Serial Wire Debug Protocol

harshan

Greetings,
               sir, i am working on serial wire debug protocol and till now i succeeded in halt,write,erase,and reset the target. now i am trying to implement breakpoints and watch points on my custom debugger. for break point i read "the definitive guide to cortex m3 by joseph yiu" book as per that i put the address on fpb comparator register, and when ever target program counter hit the address automatically the target was break and halt, till now every thing was fine, but now i want to continue the target from where it was halted. if i reset the target then the pc is resetting and target is runs from starting. hear i need to continue the target how could i achieve so that i can continue further, i hope you understand clearly.

Thanks and regards
Harshan.

Parents Reply Children
  • 0 in reply to Joseph Yiu

    Greetings and Thanks for quick reply

    after single step C_STEP i am unable to clear C_HALT bit which gives unpredictable behavior. i done following steps

    halted the core

    set the break point 1

    set the break point 2

    reset the target( target under run)

    after hitting the first break point core halted

    single step with C_STEP in DHCSR Register

    trying to Continue by clearing C_HALT in DHCSR which i got unpredictable behavior.

    suggest if i am missing any thing.

    Thanks and Regards

    Harshan

  • 0 Arm Employee Badge in reply to harshan

    Could you check to make sure you didn’t clear C_DEBUGEN (bit 0) accidentally? Thanks

  • 0 in reply to Joseph Yiu

    Thanks for Reply,

                               i send as to target

                DHCSR = 0xA05F0001, is this right??

    thanks and write.

    Harshan

  • 0 Arm Employee Badge in reply to harshan

    Yes, when you do single step, you should write

    DHSCR = 0xA05F0001UL | 0x4 ; // C_STEP

    Then wait until S_RETIRE_ST is 1.

    And then set

    DHSCR = 0xA05F0001UL; // unhalt

    Hope this helps.

    Joseph

  • 0 in reply to Joseph Yiu

    sorry for response  after a long time,

    as per above steps i performed

    when core halt after break point hit

    i tried single step the target as below

    DHCSR = 0xA05F0101

    while(!(target_read(DHCSR) & S_RETIRE_ST));

    but the target is always present inside while loop

    i tested the above logic before i put the break point and i successfully executed the breakpoint

    but after breakpoint hitting if i trying to step, it will not come out from while loop.

    Should i have to perform any thing before i single step???

    Thanks and Regards,

    Harshan