Design of a noise-free microcontroller

This paper described the new design technology for implementation of noise-free microcontroller unit (MCU), called Nfree/sup TM/ technology that is the solution proposed by Hyundai Electronics Co. Ltd. Preventing an erroneous operation due to noise is one of the basic requirements of many systems and is more seriously required by the MCU that controls the system. Also the power noise is one of the most serious noise sources that causes the MCU to malfunction. Therefore, we proposed the novel power noise preventing circuit scheme, called Nfree/sup TM/ technology. If the power falls below the voltage level of power failure, the MCU with Nfree/sup TM/ technology can be reset, frozen or stopped to preserve the system from the malfunction due to the power noise. In an MCU with Nfree/sup TM/ technology, the voltage level of power failure and the operating mode that resets, freezes or stops the MCU can be selected by software according to the applications.