Semiconductor storage device having synchronous and asynchronous modes

摘要

A method for performing scan testing using a scan chain having a plurality of storage elements is described. During a capture phase, each storage element of the scan chain stores data from a first data input of the storage element synchronously to a clock signal. And during a shift phase, a scan pattern is shifted into the scan chain in which each storage element stores data from a second data input of the storage element asynchronously with to the clock signal.

主权项

1. A method for performing scan testing using a scan chain having a plurality of storage elements, the method comprising:
during a capture phase, each storage element of the scan chain storing data from a first data input of the storage element synchronously with a clock signal; and during a shift phase, shifting a scan pattern into the scan chain in which each storage element stores data from a second data input of the storage element asynchronously with the clock signal, the shifting the scan pattern into the scan chain comprises providing a first data bit of the scan pattern to a second data input of a first storage element of the scan chain, and asserting a request signal a first time at a request input of a last storage element of the scan chain, wherein the request signal initiates storage of a data value at the second data input of the last storage element into the last storage element.