A full-scan latch is provided that may be used to incorporate design for test functionality in an integrated circuit. The full-scan latch includes a shadow latch, a multiplexer, and a slave latch. The full-scan latch has a test mode and a normal mode. When in the normal mode, the device operates as a transparent latch, passing a data input to its output. When in test mode, the device is operable to pass scan data down a scan chain and to inject scan data into the data path.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 10/115,289, filed Apr. 4, 2002. The disclosure of the prior application is considered part of and is incorporated by reference in the disclosure of this application.
An improved scan register and methods of using the same have been disclosed. In one embodiment, the improved scan register includes a master latch having a data input, a data output, and a control input. The control input is coupled to a clock signal. The master latch is operable to store data. The improved scan register further includes a scan latch having a data input, a data output, and a control input. The data input of the scan latch is coupled to the data output of the master latch. The scan latch is operable to receive and to store the data from the master latch in response to the scan latch being in a scan mode. The improved scan register may further include a functional latch having a data input, a data output, and a control input. The data input of the functional latch is coupled to the data output of the master latch. The functional latch is operable to receive and to store the data from the master latch in response to the functional latch being in a functional mode. Other embodiments have been claimed and described.
