Xu Jicai

help :some questions about the AN3275(S12 All-Access Bootloader)

Discussion created by Xu Jicai on Sep 24, 2010
Latest reply on Sep 25, 2010 by Xu Jicai

hi ,

 

1. the code below is from AN3275,the author want to erase Paged Memory of the block 0(except the page 0x3F):

------------------------------------------------------------------------------------------------------------------------------

PPAGE=0x3E;
  li16PageAddressPointer=0xBFFF;
  li16BootAddressPointer = 0xFFFF;
  while(PPAGE>li8Page)
  {
    if(*(uint8 *)(li16BootAddressPointer) != *(uint8 *)(li16PageAddressPointer))
    {
     /*
      * Erase Paged Memory
      */
      gi32FlashAddressH = PPAGE;
      for(gi32FlashAddressL=0xBF00;gi32FlashAddressL>=0x8000;gi32FlashAddressL-=0x200){
        gi16FlashDataCounter = 1;
        if (vfnFlash_Cmd(FErase))
        {
          vfnSCITxMsg(&gi8aFlashErrorMsg[0]);
          return;
        }
      }
      PPAGE--;
      li16PageAddressPointer = 0xC000;
      li16BootAddressPointer = 0x0000;
    }
    li16BootAddressPointer--;
    li16PageAddressPointer--;
    if(li16BootAddressPointer<0xF000){PPAGE = 0x36;} 
  }

------------------------------------------------------------------------------------------

but ,in my opinion ,the code below is enough for erase those flash:

----------------------------------------------------------------------------------------------------

PPAGE=0x3E;
  while(PPAGE>li8Page)
  {
      gi32FlashAddressH = PPAGE;
      for(gi32FlashAddressL=0xBF00;gi32FlashAddressL>=0x8000;gi32FlashAddressL-=0x200){
        gi16FlashDataCounter = 1;
        if (vfnFlash_Cmd(FErase))
        {
          vfnSCITxMsg(&gi8aFlashErrorMsg[0]);
          return;
        }
      }
      PPAGE--;
   }

---------------------------------------------------------------------------------------------------------------

could you tell me why the author add the other statement, thanks!

 

 

2.  it seems that the author want to write the user‘s reset vector to 0xEFFE,but it doesn’t work,could you help me to solve it ,thank you!

-----------------------------------------------------------------------------------------------------------------

      if(gi32FlashAddressL >= (1 - gi16FlashDataCounter))  //Reset Vector
      {
        if(!S19UpdatingLoader)
        {
          gi16FlashDataCounter--;
          gi16FlashDataCounter--;
          ResetVector = *(uint16 *)(&gi8aS19Buffer[gi16FlashDataCounter+4]);
        }
      }
     
      gi16FlashDataCounter >>= 1;
      /* A single S19 record line shouldn't be longer than 0x20 bytes*/
      li8Error = vfnFlash_Cmd(Program);
      gi8S19Status &= ~((1<<S19RxComplete)|(1<<S19RxOk));
     
      if (!--li8LineCounter)
      {
        SCI0DRL = '.';
        li8LineCounter = 0x20;
      }
     
    }
  }
  if (S19UpdatingLoader)
  {
    vfnSCITxMsg(&gi8UpdateLoaderMsg[0]);
    vfnpUpdateFn();
  }
  else
  {
    gi16FlashDataCounter=1;
    gi32FlashAddress = 0xEFFE;
    gi8FlashBlock = 0;
    gi16pFlashDataPtr = (uint16)&ResetVector;
    (void)vfnFlash_Cmd(Program);
  }

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