Good catch, Ken! ----- Original Message ----- From: "Ken Pergola" To: Sent: Tuesday, March 09, 2004 4:41 PM Subject: Re: [EE:] DS1631 I2C Temperature Sensor - Software Power-on reset command > T H R E A D U P D A T E: > --------------------------- > > Just in case anyone works with the Dallas/Maxim DS1631/DS1631A/DS1731 > temperature sensors, here is the response I received from Dallas/Maxim > regarding the problem of the DS1631 NACKing the SOFTWARE POR command instead > of ACKing it: > > > ----- > "Yes - this has been reported before. I don't think the design specification > included the software POR in the set of user commands. There are other test > mode commands to unlock and access trim registers, measure internal clock > frequencies, etc. I suspect the designer didn't worry about whether the > state machine acknowledges these test mode commands, and may have > deliberately forced a NACK so that they would behave as any actually invalid > command." > ----- > > > It's no biggie, but it's just something that you need to be aware of. > > In a nutshell, the SOFTWARE POR command works fine -- just generates a false > negative -- you just have to expect a NACK from the sensor instead of an ACK > (that you would normally expect). This is important to keep in mind if you > are performing any I2C/SMBus error handling. > > Hope this helps. > > Best regards, > > Ken Pergola > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.