Abstract: A computer processing unit (CPU) module is described. The present CPU module accommodates a CPU and includes a power supply, a power good detection circuit and a clock speed selector, all of which are integral to the CPU module. The power supply provides the CPU module the ability to convert power supplied to the CPU module to power as needed by the CPU. The power good detection circuit provides the CPU module the ability to notify the mother board of a power supply to the CPU which is below the operating voltage of the CPU (e.g., a power failure or insufficient voltage). The clock speed selector provides the CPU module the ability to automatically set the clock speed to that required by the CPU without modification to the BIOS stored on the mother board or changing components.

Abstract: A computer processing unit (CPU) module is described. The present CPU module accommodates a CPU and includes a power supply, a power good detection circuit and a clock speed selector, all of which are integral to the CPU module. The power supply provides the CPU module the ability to convert power supplied to the CPU module to power as needed by the CPU. The power good detection circuit provides the CPU module the ability to notify the mother board of a power supply to the CPU which is below the operating voltage of the CPU (e.g. a power failure or insufficient voltage). The clock speed selector provides the CPU module the ability to automatically set the clock speed to that required by the CPU without modification to the BIOS stored on the mother board or changing components.

Abstract: A voltage discharge circuit discharges the voltage across a charge storage device, such as a capacitor, at an output of a power supply. The discharge circuit may be used, for example, in a contrast power supply for an LCD panel. The discharge circuit uses one or more switches to control the coupling between the output capacitor and a discharge element, such as a resistor. When the power supply is enabled, the discharge resistor is not coupled to the output capacitor, so that the discharge circuit does not significantly affect the operation of the power supply. When the power supply is disabled, the switches couple the discharge resistor to the output capacitor to discharge any accumulated voltage at a relatively fast rate. For a contrast power supply for an LCD display, a switching power supply is preferred.

Abstract: A battery monitor system is disclosed comprising a microcontroller which monitors voltage inputs from a power adapter and a rechargeable battery. The power adapter includes a voltage source and a current source which outputs two current levels. A thermistor is thermally coupled to the battery, and the microcontroller receives voltage inputs from the battery and the thermistor. The microcontroller monitors and processes the voltage inputs to detect a predetermined voltage change corresponding to a change in the battery temperature and/or voltage level which indicates a fully charged battery. The level of the current which is provided to the battery from the current source is under the control of the microcontroller, such that the battery is maintained in a fully charged state.

Abstract: In a digital processing system in which a plurality of control units communicate with each other and with memory over a common bus, an arbitration circuit associated with each of the control units tests for priority among the units requesting access to the bus, granting access to the highest priority unit as soon as the bus is not busy. Priority is determined by priority numbers assigned to each unit. Priority is tested simultaneously in each unit in synchronism, each unit using common lines on the bus for both input and output to establish which unit has highest priority.