| 摘要 |
PURPOSE: A method for converting a suspend/active mode in a USB(Universal Serial Bus) core is provided to decrease power consumption by converting the active mode into the suspend mode in an external ROM embedding a program including a suspend mode conversion function and recovering the suspend mode as the active mode without the fault of a device. CONSTITUTION: If a suspend mode conversion command is inputted(S11), a decoder turns on an internal switch for supplying a power to various element circuits of a microcomputer so that a minimum power is supplied to the internal portion of the microcomputer(S12). The decoder provides a signal to an interrupt generator during a delay time(Td) for generating an interrupt(S13). The microcomputer executes a program of a designated specific address in an external ROM by the generated interrupt(S14). A switch is turned on by the execution of the program for blocking a power supplied to a peripheral circuit unit(S15). The embedded program blocks that the power is supplied to the peripheral circuit unit, and enters an idle state(S16). The signal, which turns on the internal switch, is outputted after the delay time(Td) for blocking the power of the external ROM(S19).
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