Searching \ for '74 programmer' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devprogs.htm?key=programmer
Search entire site for: '74 programmer'.

Truncated match.
PICList Thread
'74 programmer'
1997\01\09@182938 by TONY NIXON 54964

flavicon
picon face
I am 3/4 way through a program which uses a PIC'74. Also I have
working code on other 74's. I now need to program more of these
devices but I think the 74 has turned into a 74'A' which is slightly
different from the original.
I downloaded the data sheet for this chip but at 350 + pages I am
sure to miss something.
My question is - will the 74'A' devices program in a programmer
designed for the original 74?

Thanks for any help.

Best regards for the new year
Tony


Just when I thought I knew it all,
I learned that I didn't.

1997\01\09@225143 by Bob Blick

flavicon
face
>My question is - will the 74'A' devices program in a programmer
>designed for the original 74?

Yes and no. The configuration fuses are different, and I do not believe it
is merely the addition of the brown-out fuse, I think the fuses might have
been shuffled around, so blowing the fuses as if it were a 16c74 may not
blow the fuses in the pattern you chose.

Anyway, depending on your programmer, you may be able to hack the setup
files the programmer uses, or maybe not. I have a Needham's EMP-20, and it
does both the 74 and the 74a, but the user is not given the opportunity to
patch the programming parameters.

-Bob

1997\01\09@233729 by Jim Robertson

flavicon
face
At 10:28 AM 1/10/97 GMT+1100, you wrote:
>I am 3/4 way through a program which uses a PIC'74. Also I have
>working code on other 74's. I now need to program more of these
>devices but I think the 74 has turned into a 74'A' which is slightly
>different from the original.
>I downloaded the data sheet for this chip but at 350 + pages I am
>sure to miss something.
>My question is - will the 74'A' devices program in a programmer
>designed for the original 74?
>
>Thanks for any help.
>
>Best regards for the new year
>Tony
>
Tony,

Do this:

Reverse the PWRTE bit, if you want it "ON" select it as "OFF" and vice
versa.

Do not code protect the 16C74A! You will not be able to erase the code
protection bits if you do.

The Brownout will not be available on you "A" part. It will (should!) be
turned "OFF" by default by your programmer.

There are extra code protect bits in the "A" part but as you are not
programming them they do not matter.

All the other config bits, ID etc are the same!

Just remember to not code protect the "A" part and you should be ok.

Jim

More... (looser matching)
- Last day of these posts
- In 1997 , 1998 only
- Today
- New search...