Abstract: A microcontroller unit (MCU) having a primary, or main, processing unit, a secondary processing unit coupled to the primary processing unit, and a common memory coupled to the primary and secondary processing units is disclosed. A functional compare module is coupled to the primary processing unit and the secondary processing unit for comparing a primary output of the primary processing unit and a secondary output of the secondary processing units to detect a fault if the primary output and the secondary output are not the same. The invention provides a method for detecting a fault in the MCU including the steps of reading a control algorithm stored in the common memory by the primary processing unit, reading the control algorithm stored in the common memory by the secondary processing unit, comparing the primary output and the secondary output and responsively detecting a fault, if the primary output does not match the second output.

Abstract: A method and circuit for determining the health of a microcontroller is provided having a circuit that includes a bus, a CPU coupled to the bus and a register coupled to the bus. A memory is also coupled to the bus. The memory is utilized by the first CPU. A controller is coupled to the register for controlling reading of the memory. The register generates a signature in response to the memory. The controller compares the reference signature and the second signature. The controller generated a fault signal when the reference signature is unequal to the second signature.

Abstract: 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.

Abstract: A method and circuit for determining the health of a microcontroller is provided having a circuit that includes a bus having data streams thereon. A first CPU is coupled to the bus. A linear feedback shift register is coupled to the bus and generates a signature in response to the data streams. A memory is coupled to the bus. The memory is utilized by the first CPU. A controller is coupled to the register for controlling the reading of the data streams. The register generates a second signature in response to the data stream. The controller compares the reference signature and the second signature. The controller generates a fault signal when the reference signature is unequal to the second signature.

Abstract: A microcontroller unit (MCU) having a primary, or main, processing unit, a secondary processing unit coupled to the primary processing unit, and a common memory coupled to the primary and secondary processing units is disclosed. A functional compare module is coupled to the primary processing unit and the secondary processing unit for comparing a primary output of the primary processing unit and a secondary output of the secondary processing units to detect a fault if the primary output and the secondary output are not the same. The invention provides a method for detecting a fault in the MCU including the steps of reading a control algorithm stored in the common memory by the primary processing unit, reading the control algorithm stored in the common memory by the secondary processing unit, comparing the primary output and the secondary output and responsively detecting a fault, if the primary output does not match the second output.