| 摘要 |
A communication apparatus includes a comparator (11) comparing the voltage at one external bus (X0) with that at another external bus (X1), and an oscillator (12). The comparator has a high speed operation mode and a low speed operation mode, and the oscillator (12) has an oscillating operation mode and a non-oscillating operation mode. A sleep signal (SLP) is supplied to the communication apparatus, to put the comparator in the low speed operation mode and put the oscillator in the non-oscillating operation mode. When a fall or a rise is detected in an output of the comparator, the oscillator is changed to the oscillating operation mode, and thereafter, the comparator is changed to the high speed operation mode. <IMAGE> |
