Trouble programming older PIC 16C84 and 16C71

[Lothar Behrens]

Hi,

I have a PICSTART microcontroller programmer and some 16C84 and one
16C71. Both couldn't be programmed, but the chips
were in stock (in an ESD save box). One is an EEPROM type and the
other an EPROM type.

I have measured the programming voltage and it is about 13V. The chip
seems to be programmed in very less time compared to a verify.

Also I have tested with a simple frequency counter if there is any
frequence on the programming pin 13 (16C84).
While blank testing the pin measures about 4 KHz and the pin 12 about
29 KHz. That is not precise but it shows some traffic ;-)

But then when programming, no traffic is there also no traffic on
clock. This is on both reading and programming.

To ensure that the programmer isn't the problem I like to do some more
checks.

My system is Windows 2000 and the programmer software is the
MPS16B.EXE version 5.00.00.

What else could I do?

(The analog multiplexer chip MC74HC4066N and the 4x open collector
NAND SN74HC03N)

What function do they have?

There are several other programmer software packages (GPL) that I
could use. Which one works with the orginal programmer?
(PICSTART-16B1 Firmware V2.0)

The 16C84 could be programmed incircuit. What software (GPL) could I
use to programm it on parallel port using AN589?
Is the source code of that AN available on net?

There is an open source programmer (usbpicproc) that is more modern
and does support more chips. Makes this the old one obsolete?

I don't believe now that the chips that should be programmed are the
cause of failure.

Thanks

Lothar

 

[Jon Kirwan]

I have a PICSTART microcontroller programmer and some 16C84 and one
16C71. Both couldn't be programmed, but the chips
were in stock (in an ESD save box). One is an EEPROM type and the
other an EPROM type.

I think the C84 is pretty old. I can't remember the C71, at all.
Anyway, you don't describe what you mean by "couldn't be programmed"
very well. I gather you could find it on the programming list, which
surprises me a little with MPLAB v5 (I think you may need the archived
5.70.40 version, at least)... as you go on to explain some
observations during programming. On OTP parts (somehow, my memory
tells me that C parts are OTP, but I might be wrong about the two you
mentioned), I recall the need for 13.25V for programming, allowed to
drop to something like 12.75V worst case, so the 13V you mentioned
sounds about right. Programming time might be a lot less, if you are
only programming a few bytes, than verify which may require comparing
all of the bytes in the chip memory. I'm not sure about that, though.

I'd have to download the programming specification and look at it,
though, regarding the clock pins. I'd imagine that if you see
activity during blank check, that you'd probably see activity during
reading, if not programming. So that is interesting.

Which version of PICSTART do you have? There were some older ones
without the modification that allows them to download new code from
MPLAB (which is stuffed into its install directories when you install
MPLAB.) The newer ones have the programmable chip in them and MPLAB
will offer the option to download the newest code into them. And
Microchip may still offer the update to modify older ones (it's just a
matter of opening the box and replacing a chip with a module they
sell, if I recall.)

What I'm worried about is not only support for the C84 in MPLAB, but
also support for it in the code on the PICSTART unit. Also, in a case
or two that I recall, I had to create an adapter to plug the chip to
be programmed into before inserting it into the ZIF on the PICSTART.
It's possible that you may have that problem in this case, so I'd
recommend looking around (googling?) for that possible problem with
the old parts you have.

So,
(1) MPLAB should support the part and, I think, should be at least
version 5.70.40 (found in archives on Microchip site.) And
you must correctly select it, obviously.
(2) PICSTART must support the parts in its firmware, as well. And
this may mean that you need to update the firmware.
(3) Possible adapter may be required.

I'm a bit lazy right now and don't want to read the programming sheets
on these parts. Apparently, the C84 is at its END OF LIFE and the C71
is MATURE.

PIC16C84:
http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010180
http://ww1.microchip.com/downloads/en/DeviceDoc/30445c.pdf
http://ww1.microchip.com/downloads/en/DeviceDoc/30262e.pdf

PIC16C71:
http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010155
http://ww1.microchip.com/downloads/en/DeviceDoc/30272a.pdf
http://ww1.microchip.com/downloads/en/DeviceDoc/80154a.pdf
http://ww1.microchip.com/downloads/en/DeviceDoc/30298d.pdf
http://ww1.microchip.com/downloads/en/DeviceDoc/30277d.pdf

I've added some of the above links to help anyone else who may want to
do a little confirmation of something before writing to you about
this. Something that you could have done, but since I took the time I
included it here. I've also added comp.arch.embedded to the list,
because really that is the newsgroup where you are more likely to find
informed responses on this topic.

Jon