Atmel 89C51RD2 programming problem

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

Reply to
ted
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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

Reply to
Schwob

Thanks Robert, but I sorted out the programming problem. The Atmel part does not like programming hex records that straddle 128 byte page boudnaries. Rewriting the hex loader solved the problem

I think it only applies to the 40 pin DIL part , I am not sure

In a way I am glad our distributor pointed us to the Atmel part, It is 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

Reply to
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.
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Reply to
Tilmann Reh

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

Reply to
Jim Granville

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.
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Reply to
Tilmann Reh

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