Method and circuit for analysis of the operation of a microcontroller using signature analysis of data and instructions

摘要

A method and circuit for determining the health of a microcontroller is a bus having a data line and instruction line. A first CPU is coupled to the bus. A reference memory stores a reference signature. A shift register is coupled to the bus and generates a second signature in response to the data line and instruction line. A controller is coupled to the register and the reference memory for controlling reading of the data line and instruction line. The controller compares the reference signature to the second signature. The controller generates a fault signal when the reference signature is unequal to the second signature.