Integrated Circuit Having Inverse Bit Storage Test

Abstract

An integrated circuit is provided having a memory storing first and second strings of bit values, each bit value in the second string being the logical inverse of a bit value at a corresponding bit position in the first string, and a processor configured to test whether the bit values of the second string are the inverse of the bit values at respective corresponding bit positions of the first string by combining the corresponding bits of the first and second strings.

1 . An integrated circuit comprising:
 a memory storing first and second strings of bit values, each bit value in the second string being the logical inverse of a bit value at a corresponding bit position in the first string; and   a processor configured to test whether the bit values of the second string are the inverse of the bit values at respective corresponding   bit positions of the first string by combining the corresponding bits of the first and second strings.   
     
     
         2 . An integrated circuit according to  claim 1 , configured and programmed to perform a defensive action in the event the test fails. 
     
     
         3 . An integrated circuit according to  claim 2 , wherein the defensive action includes deleting or destroying some or all of the contents of the memory in the event the test fails. 
     
     
         4 . An integrated circuit according to  claim 3 , wherein the defensive action includes deleting or destroying the first and/or second strings. 
     
     
         5 . An integrated circuit according to  claim 3 , wherein the defensive action includes preventing the processor from executing software. 
     
     
         6 . An integrated circuit according to  claim 3 , wherein the defensive action includes resetting some or all of logic on the integrated circuit. 
     
     
         7 . An integrated circuit according to  claim 1 , wherein the first and second strings are stored at different sub-addresses within the same address of the memory.