| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce the cost and size of an integrated circuit (IC) by switching and coupling an external signal with the IC, and then multiplying valuable pins of the IC. <P>SOLUTION: In a signal processing system, equipped with the IC and an internal signal, is supplied to one pin of the IC and a 1st operation function (de-emphasis) for the signal is generated at the pin and further generated along the path of the signal. A 2nd operation function (variable attenuation) for the signal is generated in the IC. The external signal is switched and coupled with pins, and the 2nd operation function is enabled to operate on the external signal. A 2nd signal is coupled with pins with low source impedance. When the 2nd signal is switched and operating, the 1st operation function is made ineffective and the 1st signal is attenuated by a large amount. <P>COPYRIGHT: (C)2003,JPO</p> |
