05015875 is referenced by 43 patents and cites 2 patents.

A toggle-free scan flip-flop (TFSFF) is provided which is designed for use during a test mode scan operation. The toggle-free scan flip-flop has the capability of not toggling its parallel output during test mode scan operation. The TFSFF uses a master latch, which is controlled by a scan multiplexor, to selectively update two alternate slave latches. Switching logic controls the determination of which alternate slave latch is updated with the incoming data signal. An existent scan enable (SE) signal controls the switching logic, and thus, the TFSFF design requires no additional control signals for its operation. During the scan test mode, the data is clocked through the TFSFF from a Scan-Data-In terminal, and out the Scan-Data-Out terminal, without affecting the system data output Q. The shift sequence is followed by a capture interval, during which the Q output is automatically updated with the desired data to test the target logic. Thus, the logic under test is not affected by the loading of the scan test vector, since the parallel system output Q of the TFSFF does not toggle during the shifting sequence.

Title
Toggle-free scan flip-flop
Application Number
7/444208
Publication Number
5015875
Application Date
December 1, 1989
Publication Date
May 14, 1991
Inventor
Jesse R Wilson
Austin
TX, US
Grady L Giles
Austin
TX, US
Agent
Charlotte B Whitaker
Assignee
Motorola
IL, US
IPC
H03K 19/007
H03K 3/284
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