how does designer detect and fix fault in vlsi circuit ?
does large vlsi circuit contain additional test circuit ?

 

What kind of fault?

 

how does designer detect and fix fault in vlsi circuit ?
does large vlsi circuit contain additional test circuit ?

Prior to fabrication faults are detected via simulation. After fabrication, faults are detected by automated testing and the dice with faults are discarded. First silicon may have yields under 50%, but as the process is refined they can approach 99%

All chips manufactured have test circuitry in them to facilitate automated testing. Here is a link on Boundary Scan testing

http://en.wikipedia.org/wiki/Boundary_Scan

 

Fault may occur anytime
- Design
- Process
- Package

circuit design
functional design
structural design
layout design

when we design circuit on software , error can be determine by the simulation

vlsi circuit contain additional test circuit like fault modeling
stuck at faults
Bridging faults
Transistor stuck-open faults
Delay faults

error can be determine by fault simulation

we can test circuit to determine fault
Q1 what is test generation ?

Q2 scan is technique used in design for testing ?

Q3 built in self test

built in self test method that allow circuit to test their own operation