Fault modeling in Digital systems

Thread Starter

Innocent

Joined Apr 23, 2006
4
Please i need advice on how to go about this project. Where to source information concerning the project.
Thanks
Innocent
 

Papabravo

Joined Feb 24, 2006
14,463
Originally posted by Innocent@Apr 23 2006, 12:30 PM
Please i need advice on how to go about this project. Where to source information concerning the project.
Thanks
Innocent
[post=16449]Quoted post[/post]​
I'm not sure what to say on this one. What kinds of faults are you interested in modeling, and in what context. Is this related to what happens in the silicon manufacturing process? Is this related to board or system level diagnosis and repair? Give us something to go on here.
 

Thread Starter

Innocent

Joined Apr 23, 2006
4
Originally posted by Papabravo@Apr 24 2006, 03:14 AM
I'm not sure what to say on this one. What kinds of faults are you interested in modeling, and in what context. Is this related to what happens in the silicon manufacturing process? Is this related to board or system level diagnosis and repair? Give us something to go on here.
[post=16460]Quoted post[/post]​
 

Thread Starter

Innocent

Joined Apr 23, 2006
4
Originally posted by Innocent@Apr 25 2006, 08:06 AM

[post=16505]Quoted post[/post]​
Thanks for showing interest.
The area of interest is the diagnosis and repair of boards that make
the digital systems.
Thanks
 

Papabravo

Joined Feb 24, 2006
14,463
Originally posted by Innocent@Apr 25 2006, 03:10 AM
Thanks for showing interest.
The area of interest is the diagnosis and repair of boards that make
the digital systems.
Thanks
[post=16506]Quoted post[/post]​
When a board with a verified design stops working we have an easier problem than design verification. Two common board faults, shorts and opens can be modeled by SPST switches. Stimulus response testing can localize and detect these faults.

Moving to the components we have with outputs the "stuck at 1" and the "stuck at 0" faults. These are modeled with a pullup or a pulldown resistor. In actual diagnosis a 1K resistor connected to Vcc or Ground will reveal outputs with weak drive which accounts for their inability to drive an output to a stable state.

A broken input, as a result of static damage, can be modeled with an SPST switch. Again stimulus response testing can be used to localize and detect these faults.

Signature analysis is another diagnostic tool that can be used to quickly verify the proper function of a board. Deviation from the signatures can indicate the location of a fault. This technique was popular some years ago, but I havn't heard much about it recently. Try googling the term if you are interested.

Does this help?
 

Thread Starter

Innocent

Joined Apr 23, 2006
4
Originally posted by Papabravo@Apr 25 2006, 01:57 PM
When a board with a verified design stops working we have an easier problem than design verification. Two common board faults, shorts and opens can be modeled by SPST switches. Stimulus response testing can localize and detect these faults.

Moving to the components we have with outputs the "stuck at 1" and the "stuck at 0" faults. These are modeled with a pullup or a pulldown resistor. In actual diagnosis a 1K resistor connected to Vcc or Ground will reveal outputs with weak drive which accounts for their inability to drive an output to a stable state.

A broken input, as a result of static damage, can be modeled with an SPST switch. Again stimulus response testing can be used to localize and detect these faults.

Signature analysis is another diagnostic tool that can be used to quickly verify the proper function of a board. Deviation from the signatures can indicate the location of a fault. This technique was popular some years ago, but I havn't heard much about it recently. Try googling the term if you are interested.

Does this help?
[post=16518]Quoted post[/post]​
Thanks once again
True i will go goggling but i will appreciate if you can give me some reference materials like books or websites.
Thanks
 

Papabravo

Joined Feb 24, 2006
14,463
Originally posted by Innocent@Apr 25 2006, 09:13 PM
Thanks once again
True i will go goggling but i will appreciate if you can give me some reference materials like books or websites.
Thanks
[post=16546]Quoted post[/post]​
Peatman, J.B.,Digital Hardware Design,McGraw Hill, 1980
$0.89 on Amazon. Well worth the shipping.
 
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