What is ATPG mode?

ATPG (acronym for both Automatic Test Pattern Generation and Automatic Test Pattern Generator) is an electronic design automation method/technology used to find an input (or test) sequence that, when applied to a digital circuit, enables automatic test equipment to distinguish between the correct circuit behavior and …

How the test patterns are generated in ATPG?

ATPG algorithm is a two-stage process. Random Test Pattern Generation: In this method, we randomly generate test patterns and select those patterns that detect undetected faults. There is no target fault. Since test patterns are generated by trial and error method, this is a pretty fast and inexpensive process.

Which is more efficient ATPG algorithm?

PODEM proves to be more efficient as compared to a D-ALG because it limits its search space only to Primary Inputs (PIs) of the circuits. D-ALG on the other hand has a search space comprising of all the internal nodes of the circuit along with the PIs. The first ob- jective of the algorithm is to sensitize the fault.

What is the difference between ATPG and BIST?

The ATPG compression approach uses on-chip pattern generator as a decompressor. Pre-compressed deterministic patterns are stored in the tester. In comparison, the logic BIST approach uses an on-chip pseudo-random pattern generator (PRPG).

What is combinational ATPG and sequential ATPG?

ATPG for combinational blocks in sequential circuits require more than one pattern. Final pattern is according to combinational ATPG (that sensitize the fault and propagates the effect to a primary output) and all other initial patterns are to bring the secondary inputs to their required value.

What is sequential depth in ATPG?

sequential depth is the number of capture cycles executed before unloading your scan chains.

Why is BIST used?

The main purpose 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.

Is the test strategy in logic BIST?

Two test strategies are used to test virtually all IC logic: automatic test pattern generation (ATPG) with test pattern compression and logic built-in self-test (BIST).

What is stuck at 0 and stuck at 1 faults?

When a signal, or gate output, is stuck at a 0 or 1 value, independent of the inputs to the circuit, the signal is said to be “stuck at” and the fault model used to describe this type error is called a “stuck at fault model”.

What is abort limit in DFT?

Set Abort Limit Specifies the abort limit for the test pattern generator. Set Atpg Compression Specifies for the ATPG to perform dynamic pattern compression. Set Atpg Limits Specifies the ATPG process limits at which the tool terminates the ATPG process.

What are the types of BIST?

BIST techniques are classified in a number of ways, but two common classification of BIST are the Logic BIST (LBIST) and the Memory BIST (MBIST).

What is initiated bit?

Initiated BIT (IBIT) – Usually invoked following a failure, IBIT initiates tests to isolate a fault within a system or subsystem. In general, IBIT will halt the current application, run its tests, and either resume or restart the application.

What is ATPG (automatic test pattern generation)?

Automatic Test Pattern Generation, or ATPG, is a process used in semiconductor electronic device testing wherein the test patterns required to check a device for faults are automatically generated by a program. ATPG is a decision problem. Consider a combinational circuit with four primary inputs (a, b, c, d).

What does ATPG stand for?

The main contribution of this paper is what we call an Automatic Test Packet Generation (ATPG) framework that automatically generates a minimal set of packets to test the liveness of the underlying topology and the congruence be- tween data plane state and con\\fguration speci\\fcations.

What is ATPG in DFT (VLSI)?

Automatic Test Pattern Generation (ATPG) in DFT (VLSI) Test pattern generation (TPG) is the process of generating test patterns for a given fault model. If we go by exhaustive testing, in the worst case, we may require 2 n (where n stands for no. of primary inputs) assignments to be applied for finding test vector for a single stuck-at fault.

How does ATPG handle test failures?

Test packets are sent periodically and detected failures trigger a separate mechanism to localize the fault. ATPG can de- tect both functional (e.g., incorrect \\frewall rule) and per- formance problems (e.g., congested queue).