摘要 |
<p>PURPOSE: To automatically place a chip to a state where power consumption is reduced by making the chip monitor its own operation and placing the chip in the state where power is reduced in response to a monitoring process for judging that the chip is in a prescribed state. CONSTITUTION: A power consumption reduction logic 500 reduces the power consumption of an FDC by stopping internal clocks generated in a clock generation part 509 and adding power consumption reduction state signals (PD-STATE) to a circuit. An REG-ACCESS logic 501 judges whether or not one of the motors of the drive of a floppy disk is turned to a possible state, whether or not a FIFO is accessed at present by a read operation or a write operation and whether or not an MSR command register is read. The REG-ACCESS logic 501 outputs REG-ACCESS signals to an automatic power consumption reduction logic 503 and the logic 503 decides whether or not to place the FDC in a power consumption reduction state in response to the signals.</p> |