• State Not Answered
  • Locked Locked
  • Replies 7 replies
  • Subscribers 22 subscribers
  • Views 1066 views
  • Users 0 members are here
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

Structure of C_INITSEC

Jürgen Breuer

hello,

I have to initialize static variables residing in sdata after setting bit XPEN in main() by myself, because in our system it is not possible to set bit XPEN prior to the initialization loop in the startup code.

For that I have to know the structure of C_INITSEC but I could not find some info, besides info about C51 where sdata is not mentioned.

Do you have got some?

Best regards

Jürgen

Parents
  • 0 in reply to Jürgen Breuer

    putting solutions into question

    Interesting you think anybody was doing such a thing before any solutions were even mentioned.

    thought it would be easyest to initialize sdata only "again" after setting XPEN

    And how is that ever going to be easier than the painfully obvious choice of just setting XPEN right there in the startup code?

    Why are you building obstacles for yourself that you can't cross?

Reply
  • 0 in reply to Jürgen Breuer

    putting solutions into question

    Interesting you think anybody was doing such a thing before any solutions were even mentioned.

    thought it would be easyest to initialize sdata only "again" after setting XPEN

    And how is that ever going to be easier than the painfully obvious choice of just setting XPEN right there in the startup code?

    Why are you building obstacles for yourself that you can't cross?

Children
  • 0 in reply to HansBernhard Broeker

    To satisfy your interest I tell you that our software is running on different hardware.
    To detect the hardware at hand we have to check different things like input voltages but also complex things like protocols on serial interfaces. Things you really do not want to do from startup code.
    Unfortunately we have to change value of XPERCON register to meet the requirements to detect several interface cards. But XPERCON is not changeable after setting XPEN, so there was our problem.

    I solved it by creating an assembler routine, copying the complete initialization routine into it and prohibiting writing to memory if the address is not in range 0xE000 - 0xEFFF

    In doing that I did not have to understand the comlete structure of the initialization routine but only to find the writing to the target address.

          CMP   DPP3,#3
      JMPR  cc_NE,NoSdataInit

      JNB   R3.15,NoSdataInit   ; DPP3
      JNB   R3.14,NoSdataInit   ; DPP3
      JNB   R3.13,NoSdataInit   ; <0xE000
      JB    R3.12,NoSdataInit   ; >0xE7FF
      JB    R3.11,NoSdataInit   ; >0xE7FF
      MOVB  [R3],RL5            ; wirte value (1 Byte) DPP3:R3
NoSdataInit:
...
...
StoreBit1:
;bits are not in sdata do not write
;      MOV   [R3],R4

    Thank you for making me think harder ;-)

    Jürgen

  • 0 in reply to Jürgen Breuer

    "I did not have to understand the comlete structure of the initialization routine but only to find the writing to the target address."

    You are assuming that there's nothing in the "other" parts that could interfere with this...