Method and system for detecting a mode of operation of an integrated circuit, and a memory device including same

Abstract

A threshold detection circuit for developing a mode trigger signal includes an input that receives an input signal. In response to the input signal having approximately an input threshold value for a triggering time, the threshold detection circuit activates the mode trigger signal on an output. In response to the input signal being substantially different from the input threshold value or the input signal not having the input threshold value for the triggering time, the circuit deactivates the mode trigger signal. The threshold detection circuit may be contained in a variety of different mode detection circuits for detecting when an integrated circuit is to be placed in a test mode or other desired mode of operation, and such mode detection circuits may be contained in a variety of different types of integrated circuits, such as memory devices generally and SRAMs specifically.

1 . A method of detecting a test mode of operation of an integrated circuit, the integrated circuit including an external terminal coupled to an input circuit contained within the integrated circuit, the input circuit having an input threshold value, and the method comprising: 
 applying a test signal to the external terminal;    and detecting a test mode of operation when the applied test signal is maintained at approximately the input threshold value for a triggering time.    
   
   
       2 - 64 . (canceled)