We have an 87c51 system which uses a 93C06 EEPROM to hold configuration data. The units operate 7/24 and on average lost their data every few months. Sometimes ( if not always ) they erase to 0ffh's. I cannot find anything wrong with the micro code. Has anyone experience hardware errors with these devices? Thanks, Arthur
93C06 data corruption
Started by ●January 18, 2004
Reply by ●January 19, 20042004-01-19
On Mon, 19 Jan 2004 13:00:45 +1100, the renowned "Arthur Richards" <fake@address.com.au> wrote:>We have an 87c51 system which uses a 93C06 EEPROM to hold configuration >data. The units operate 7/24 and on average lost their data every few >months. Sometimes ( if not always ) they erase to 0ffh's. I cannot find >anything wrong with the micro code. > >Has anyone experience hardware errors with these devices?Usually something to do with the micro controlling them.. and electrical noise or improper startup and shutdown. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Reply by ●January 19, 20042004-01-19
Arthur Richards wrote:> We have an 87c51 system which uses a 93C06 EEPROM to hold configuration > data. The units operate 7/24 and on average lost their data every few > months. Sometimes ( if not always ) they erase to 0ffh's. I cannot find > anything wrong with the micro code. > > Has anyone experience hardware errors with these devices? >Watch out for brownouts (voltage dips) small enough to make the -51 misbehave but not low enough to activate the write protection of the EEPROM. We had a similar problem with a 8051 and EEPROM, and the problem was cured with a brownout detector / reset chip. It seems that the 8051 family chips start to misbehave and spew all kinds of rubbish on the bus lines just before dying on power starvation. HTH Tauno Voipio tauno voipio @ iki fi
Reply by ●January 19, 20042004-01-19
Hi, Perhabs you write a lot into the EEPROM and the memory has reached its max number of erasure / programming.... Yvan ********************** YBDesign http://www.ybdesign.fr ********************** Tauno Voipio <tauno.voipio@iki.fi.NOSPAM.invalid> a �crit dans le message : eEKOb.24$QR3.21@read3.inet.fi...> Arthur Richards wrote: > > We have an 87c51 system which uses a 93C06 EEPROM to hold configuration > > data. The units operate 7/24 and on average lost their data every few > > months. Sometimes ( if not always ) they erase to 0ffh's. I cannot find > > anything wrong with the micro code. > > > > Has anyone experience hardware errors with these devices? > > > > Watch out for brownouts (voltage dips) small enough to make > the -51 misbehave but not low enough to activate the write > protection of the EEPROM. > > We had a similar problem with a 8051 and EEPROM, and the > problem was cured with a brownout detector / reset chip. > > It seems that the 8051 family chips start to misbehave > and spew all kinds of rubbish on the bus lines just > before dying on power starvation. > > HTH > > Tauno Voipio > tauno voipio @ iki fi > >
Reply by ●January 19, 20042004-01-19
Spehro Pefhany schrieb:> >We have an 87c51 system which uses a 93C06 EEPROM to hold configuration > >data. The units operate 7/24 and on average lost their data every few > >months. Sometimes ( if not always ) they erase to 0ffh's. I cannot find > >anything wrong with the micro code. > > Usually something to do with the micro controlling them.. and > electrical noise or improper startup and shutdown.Especially power up might cause problems, if CS is not explicitly held inactive (low) until VCC has reached the operating range. If you are interfacing to the '51 directly (particularly CS), this might be an issue. There is a detailed AN on the website of STMicroelectronics about this. -- Dipl.-Ing. Tilmann Reh Autometer GmbH Siegen - Elektronik nach Ma�. http://www.autometer.de ================================================================== In a world without walls and fences, who needs Windows and Gates ? (Sun Microsystems)
Reply by ●January 19, 20042004-01-19
Arthur Richards wrote:> We have an 87c51 system which uses a 93C06 EEPROM to hold configuration > data. The units operate 7/24 and on average lost their data every few > months. Sometimes ( if not always ) they erase to 0ffh's. I cannot find > anything wrong with the micro code. > > Has anyone experience hardware errors with these devices?I recently heard of an inherent weakness of all EEPROMs at low voltage. I'd have to look it up. The essence was to have a fast transition from 0V to operating and back. Especially recommended was a shunt resistor over the power supply to make the power off faster. Eg 1k @ 5V or so. Rene -- Ing.Buero R.Tschaggelar - http://www.ibrtses.com & commercial newsgroups - http://www.talkto.net
Reply by ●January 20, 20042004-01-20
Reply by ●January 20, 20042004-01-20