Logic built-in self-test (or LBIST) is a form of
built-in self-test
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
*lower repair cycle times
or constraints such as:
*limited technic ...
(BIST) in which hardware and/or software is built into
integrated circuit
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...
s allowing them to test their own operation, as opposed to reliance on external
automated test equipment
Automatic test equipment or automated test equipment (ATE) is any apparatus that performs tests on a device, known as the device under test (DUT), equipment under test (EUT) or unit under test (UUT), using automation to quickly perform measurements ...
.
Advantages
The main advantage of LBIST is the ability to test internal circuits having no direct connections to external pins, and thus unreachable by external automated test equipment. Another advantage is the ability to trigger the LBIST of an integrated circuit while running a built-in self test or power-on self test of the finished product.
Disadvantages
LBIST that requires additional circuitry (or
read-only memory
Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing sof ...
) increases the cost of the integrated circuit. LBIST that only requires temporary changes to
programmable logic
A programmable logic device (PLD) is an electronic component used to build reconfigurable digital circuits. Unlike digital logic constructed using discrete logic gates with fixed functions, a PLD has an undefined function at the time of manu ...
or
rewritable memory avoids this extra cost, but requires more time to first program in the BIST and then to remove it and program in the final configuration. Another disadvantage of LBIST is the possibility that the on-chip testing hardware itself can fail; external automated test equipment tests the integrated circuit with known-good test circuitry.
Related technologies
Other, related technologies are
MBIST
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
*lower repair cycle times
or constraints such as:
*limited technic ...
(a BIST optimized for testing internal
memory
Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered, ...
) and ABIST (either a BIST optimized for testing
arrays
An array is a systematic arrangement of similar objects, usually in rows and columns.
Things called an array include:
{{TOC right
Music
* In twelve-tone and serial composition, the presentation of simultaneous twelve-tone sets such that the ...
or a BIST that is optimized for testing
analog circuitry
Analogue electronics ( en-US, analog electronics) are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two levels. The term "analogue" describes the proportional relati ...
). The two uses may be distinguished by considering whether the integrated circuit being tested has an internal array or analog functions.
See also
*
Built-in self-test
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
*lower repair cycle times
or constraints such as:
*limited technic ...
*
Built-in test equipment
Built-in test equipment (BITE) for avionics primarily refers to passive fault management and diagnosis equipment built into airborne systems to support maintenance processes. Built-in test equipment includes multimeters, oscilloscopes, discharge pr ...
*
Design for test Design for testing or design for testability (DFT) consists of IC design techniques that add testability features to a hardware product design. The added features make it easier to develop and apply manufacturing tests to the designed hardware. Th ...
*
Power-on self-test
A power-on self-test (POST) is a process performed by firmware or software routines immediately after a computer or other digital electronic device is powered on.
This article mainly deals with POSTs on personal computers, but many other embed ...
External links
Built-in Self Test (BIST)*
{{DEFAULTSORT:Logic Built-In Self-Test
Integrated circuits