Patent ID: 7345497
Filing Date: 2008-03-18
Classification: G06F,H01L

Abstract:
1. A protection circuit, comprising: at least one shielded line pair arranged to cover an area to be protected over a semiconductor device, the at least one shielded line pair including two shielded lines, and each shielded line having only one route from a start point to an end point; a signal generator for applying a potentional to the start points of the shielded lines of the shielded line pair; a detector for comparing a potential difference between the end points of the shielded lines of the shielded line pair with a reference value to output a fraud detection signal according to a result of the comparison; a plurality of said shielded line pairs; the signal generator applies a potential to start points of shielded lines of one of the plurality of shielded line pairs; and the protection circuit further includes a switching circuit for transmitting to the detector the potentials at the end points of the shielded line pair to which the potential is applied by the signal generator.