Abstract: A method and apparatus are provided for downloading a program by using hand-shaking in a digital signal processor (DSP), in which the program stored at an external memory is downloaded to an internal memory by using the hand-shaking in an asynchronous system having a dual CPU, wherein current operation of the digital signal processor is temporarily held to shorten a downloading time.

Abstract: A first module is operated at a first power supply voltage and is blocked from the first power supply voltage in a power-off mode. A second module is operated at a second power supply voltage higher than the first power supply voltage and is supplied with the second voltage even in the power-off mode. An interface circuit is connected between the first and second modules. The interface circuit includes a voltage level converting circuit having an input control circuit. The input control circuit allows the voltage level converting circuit to carry out a normal voltage converting operation in a normal operating mode, while interrupting a leakage current path of the voltage level converting circuit due to an input signal in an unstable status in the power-off mode.

Abstract: A first module is operated at a first power supply voltage and is blocked from the first power supply voltage in a power-off mode. A second module is operated at a second power supply voltage higher than the first power supply voltage and is supplied with the second voltage even in the power-off mode. An interface circuit is connected between the first and second modules. The interface circuit includes a voltage level converting circuit having an input control circuit. The input control circuit allows the voltage level converting circuit to carry out a normal voltage converting operation in a normal operating mode, while interrupting a leakage current path of the voltage level converting circuit due to an input signal in an unstable status in the power-off mode.

Abstract: An apparatus for driving a bus with low power consumption, capable of reducing power consumption by reducing the width of the change in the level of a bus driving voltage transmitted through the data bus and a method therefor are provided. In the apparatus for transmitting a first or second bus driving voltage corresponding to input data instead of the input data to a bus receiving apparatus through a data bus, a first voltage transmitter transmits the first bus driving voltage, which corresponds to input data having a high level, to the data bus in response to a first control signal. A second voltage transmitter transmits the second bus driving voltage, which has a level that is lower than the level of the first bus driving voltage by a first predetermined level and corresponds to a low level of the input data, to the data bus in response to the first control signal. A first control signal generator outputs the first control signal in response to the input data.