Understanding Embedded Chipsgreenspun.com : LUSENET : TimeBomb 2000 (Y2000) : One Thread
I think the hardest thing for me to understand was these chips. I found this on Wisconsin Y2K site. Thought it might help others to see how these little buggers can cause so much problems. I hope I cut and pasted this correctly so its not a mixed up mess.
22 State of Wisconsin - Department of Administration Visit our web site at http://y2k.state.wi.us/ l Test procedures l Test results l Define an action plan for the device
Perform an inventory of the systems Device Identification
The bottom line that needs to be asked is "what goes into the inventory". The answer is any piece of equipment that is digital.
The harder question is what is a digital device and how to identify it. Embedded microprocessors are prevalent throughout any facility or organization, some are obvious but most are not. Some devices may have nothing that shows you a time or day but has a maintenance or service log internally that can only be accessed by a service computer. Here are some guidelines to help identify whether or not a device should be inventoried:
l Does the device display the time, date, or day or week? l Does the device have any kind of digital readout? The display could be any kind of alphanumeric display. l Does the device have a keypad or buttons for entering numerical data? l Is the function of the device to monitor or log errors or problems in the facility? l Is the device "programmable" for day or week, holiday, or scheduled changes in it's normal operations? l Does the device report any kind of error conditions in any form to the operator or to another device? This can include something as simple as a light, LED, or audible alarm. l Is the device a critical component in a life or safety critical area of the facility?
A useful resource when investigating a device is the documentation that came with the device (operators manual, service manual, etc.), Here are some terms to look for when searching through the manuals:
Battery or battery backup This could indicate the existence of a clock calendar chip which often requires a battery.
Calendar Synonymous with date.
Clock or Clock/Calendar The chip that keeps track of the date is often referred to as a clock/calendar chip.
Error reporting Any digital form of error reporting can imply an internal date for when the error occurred.
Log, error log, or service log Any data logging often includes a date and time. This is a major source or problems.
RTC or Real Time Clock Real time often implies a date/time function.
Time A device that only shows the time may also have an internal date that is not shown. The clock chips generally have time and date together.
Timer Many devices that use timers use date and time calculations.
TOD or Time Of Day clock Time of day almost always includes a date, either displayed or hidden.
It is critical to the success of this project that you remember to use your own judgement, this list does not define every possible scenario that you will find. There is no substitute for stopping and thinking about the use of a specific device (particularly by the person who uses or services the device). If you are not sure if the device has an embedded computer in it but the device is critical to the operation of a health or safety device, add it to the inventory!
-- maji (majiWI@yahoo.com), March 15, 1999
We should have expressed our thanks for this post earlier.
-- Watchful (email@example.com), March 18, 1999.
If you REALLY want to know the scoop on embedded chips, go to: http://www.tmn.com/y2k
Embedded Systems and the Year 2000 Problem (The OTHER Year 2000 Problem) http://www.tmn.com/~frautsch/y2k2.html Draft of 24 February 1999 Copyright 1998, 1999 Mark A. Frautschi, Ph.D. Shakespeare and Tao Consulting http://www.tmn.com/y2k (410) 453-9256 firstname.lastname@example.org
I recommend sending this page and bookmarking it for those wishing to understand the embedded system part of Y2K that is much harder to grasp than the software / code end of Y2K.
***looking at the new meaning of "chips and dip"***
-- Mr. Kennedy (email@example.com), March 18, 1999.