Pic16f627/8

[vdd]

Hi,

Has any one had problems with quirky programming with the P16F627/8. I'm trying to migrate from the good old p16f84. These two device share some simular operations and some pin to pin compatible. But when I tried the same function in the 84 onto the 627( the 627 has this function), the 627 had irratic and wired operation, and sometimes no function at all. I have disable the LVP and comparator in the 627. May be I missed something? Any body help please ?

 

[kchriste]

But when I tried the same function in the 84 onto the 627( the 627 has this function), the 627 had irratic

Help us help you. Which function are you talking about?

 

[Wingmax]

May be the Configuration word hasn't been set correctly.

 

[Diver300]

The general purpose registers on the pic16f627/8 start at 0x20. The registers on the pic16f84 start at 0x0c

You have to make sure that none of your code tries to use any registers in the range 0x0c - 0x1f as general purpose.

I'm sorry if you have already realise this.

 

[Nigel Goodwin]

You also need to turn off the anlogue comparators as well, but with these few small changes the 627/8 is a direct replacement for the 84.

 

[vdd]

Thanks guys,

May be I should have said I was using C compiler. So the memory location or register bank etc has been taken care of by the compiler. I think may be it's the configuration word. How do I know what is the correct word to set?

 

[Wingmax]

Check the following site:
**broken link removed**

I'm bit surprised that there's not much been said about the Configuration word, and yet it's so important. I remember I had some troubles when I first started programming the PIC. Sometimes I wasted hours looking for programming error and it turned out just a mistake on the configuration word. I wonder if many people had this problem.