Editing Built-in self-test (section)

{{Short description|Mechanism allowing a machine to test itself}}
{{refimprove|date=February 2011}}

A '''built-in self-test''' ('''BIST''') or '''built-in test''' ('''BIT''') is a mechanism that permits a machine to test itself.  Engineers design BISTs to meet requirements such as:

*high [[Reliability engineering|reliability]]
*lower [[Repair cycle|repair cycle times]]

or constraints such as:

*limited technician accessibility
*cost of testing during manufacture

The main purpose <ref>Martínez LH, Khursheed S, Reddy SM. LFSR generation for high test coverage and low hardware overhead. IET Computers & Digital Techniques. 2019 Aug 21.[https://livrepository.liverpool.ac.uk/3052312/ UoL repository]</ref> of BIST is to reduce the complexity, and thereby decrease the cost and reduce reliance upon external (pattern-programmed) test equipment.  BIST reduces cost in two ways:
# reduces test-cycle duration
# reduces the complexity of the test/probe setup, by reducing the number of I/O signals that must be driven/examined under tester control.
Both lead to a reduction in hourly charges for automated test equipment (ATE) service.