Method and system for checking rotate, shift and sign extension functions using a modulo function

• Main Authors: SCHMOOKLER MARTIN STANLEY, BUSABA FADI Y, POWELL LAWRENCE JOSEPH, WEBBER DAVID ALLAN, VADEN MICHAEL THOMAS
• Format: Patent
• Language: English
• Published: 20.09.2011
• Subjects: BASIC ELECTRONIC CIRCUITRY; CALCULATING; CODE CONVERSION IN GENERAL; CODING; COMPUTING; COUNTING; DECODING; ELECTRIC DIGITAL DATA PROCESSING; ELECTRICITY; PHYSICS

A method of discovering a fault in a circuit is disclosed. The method comprises generating a first result of a selected function by performing the selected function on an operand, wherein the selected function employs a mask. Once the function is performed, an antimask of the mask is created, and the modulo of the antimask is calculated. A modulo function of the first result of the selected function is calculated to obtain a third result. A modulo of the operand is then calculated to obtain a fourth result, and a second function is then performed on the second result and the third result to obtain a fifth result. In response to comparing the fifth result to the fourth result, a signal is propagated to indicate a fault in the circuit.