The 33989 is a monolithic integrated circuit combining many functions used by microcontrollers (MCU) found in automotive Engine Control Units (ECUs). The device incorporates functions such as: two voltage regulators, four high voltage (wake up) inputs, a 1Mbaud capable CAN physical interface, an SPI interface to the MCU and VSUP monitoring and fault detection circuitry. The 33989 also provides reset control in conjunction with VSUP monitoring and the watchdog timer features. Also, an Interrupt can be generated, for the MCU, based on CAN bus activity as well as mode changes.