In message <003301c0d49d$cc6810e0$3a5170cf@l9d1f7>, myke predko
<myke@PASSPORT.CA> writes
>Hi Nigel,
>
>What were the changes you made to the erase routines?  I have used the
>PIC16F84A in my El Cheapo without any problems, but I would like to know
>what to do if it bites somebody.

Hi Mike,

I can't remember how the routine was before, it basically developed over
a number of years - as you probably remember there were problems with
the erase routine listed in the 16C84 datasheet, and I implemented
changes based on information from the PicList. Here is the routine I
currently use.

ProgMode() turns MCLR on or off, Command() sends a command to the PIC,
Outword() sends a 14 bit value. The values send (like BegPrg) are those
listed in the datasheet. I notice I've actually commented a change for
the 16F84A

Procedure EraseAll;
Var
  i : Byte;
Begin
  {Clear Protect fuse}
  ProgMode(POn);
  Command(LdConf);
  OutWord($3FFF); {value to reset memory to}
  FOR i := 0 TO 6 Do
    Command(IncAdd);
  Command(1);
  Command(7);
  Command(BegPrg);
  Delay(ProgDelayTime);
  Command(1);
  Command(7);
  {Command(BegPrg); - removed for 16F84A}
  ProgMode(POff);
  {Clear Program memory}
  ProgMode(POn);
  Command(LdProg);
  OutWord($3FFF);
  Command(BegPrg);
  Command(ErsPrg);
  Command(BegPrg);
  Delay(ProgDelayTime);
  ProgMode(POff);
  {Clear Data memory}
  ProgMode(POn);
  Command(LdData);
  OutWord($3FFF);
  Command(1);
  Command(7);
  Command(BegPrg);
  Delay(ProgDelayTime);
  Command(1);
  Command(7);
  ProgMode(POff);
End;

--

Nigel.

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        | Nigel Goodwin   | Internet : nigelg@lpilsley.co.uk           |
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