We have been using The Philips version of the RD2 8051 chip for a
while with no
problems. As they don't seem to be made any more, we moved to the
Atmel equivalent (part number on the chip: 89C51RD2-IM, notice no "T")

However, we are having problems trying to program the Atmel chip using
the serial Intel hex ISP protocol. We never had any problems when
progamming the Philips part using the same programmer (a custom made
unit)

The only change we made was to reduce the programming voltage from
12 volts to 5. The PSEN, ALE and EA lines are all exactly as required
for
the Philips part.

The programming software when run seems to work OK, The echoed full
dot codes '.' are returned by the chip on every hex sequence sent as
they should. However, when attempting th read the contents of the chip
back, program EPROM locations 76 to 7F never seem to program
correctly, they are
stuck at FFhex. We have tried a batch of five Atmel chips, they all do
exactly the same.

Are we doing something wrong? Are there any essential differences
ebtweeen the Philips programming method and the Atmel one that we
should be aware of??

I don't think it is a problem with the Atmel part. The real question
is: is there any difference between the Philips andthe Atmel
programming methods that may be causing this??

Thanks in advance

Ted

Ted,

This one is really short, who told you that Philips does not produce
the 89C51RD2 anymore? Change your distributor!
There has been no discontinuation by of the 89C51RD2, I would know, we
are using it.

Cheers, Robert

edaudio2000@yahoo.co.uk (ted) wrote in message news:<c54bf83f.0309230101.364947bf@posting.google. com>...

schwobus@aol.com (Schwob) wrote in message news:<123e50e1.0309231757.7fcd32ec@posting.google. com>...
part does not like programming hex records that straddle 128 byte page
boudnaries. Rewriting the hex loader solved the problem


cheaper than the Philips one. Runs faster (40MHz), it is quicker to
program (no lengthy block erase command) and does not require 12 volts
for programming.

Regards

ted

ted schrieb:

Yes, I noticed that too.

No, that's not true - Philips also doesn't need the 12V for programming
(though it tolerates them).

The only "real" difference between the two chips that I'm aware
of is the 2k EEPROM in the Atmel that's missing in the Philips.

--
Dipl.-Ing. Tilmann Reh
Autometer GmbH Siegen - Elektronik nach Maß.
http://www.autometer.de

================================================== ================
In a world without walls and fences, who needs Windows and Gates ?
(Sun Microsystems)

Tilmann Reh wrote:
If you are qualifying parts, the T89C51RD2 is not quite the
same as the newer AT89C51RD2/ED2 variants.
The ED2 is the one with 2K EE, so if you used that in the
T89C51RD2, you need AT89C51ED2
ED2 family I think adds SPI, and wider Vcc, using an internal
regulator for 2.7-5.5V Vcc : So should have good EMC at 5.5V
as the core is < 2.7V.
ED2 has also added DIP40, that was missing from first data sheets.

-jg

Jim Granville schrieb:

Yes, I also found out when looking at their newest DS.

.... while the T89C51RD2 always was available in DIP40...

You easily get confused by their nomenclature!

--
Dipl.-Ing. Tilmann Reh
Autometer GmbH Siegen - Elektronik nach Maß.
http://www.autometer.de

================================================== ================
In a world without walls and fences, who needs Windows and Gates ?
(Sun Microsystems)