| 摘要 |
PURPOSE:To make it possible to use an outer pin both for a data signal input and for a control signal input and to realize the very small configuration of an LSI, by measuring the changing degree of the input signal through the outer pin. CONSTITUTION:Whether a digital input signal 4 that is inputted through an outer input terminal 1 is a digital signal or a control signal is judged by measuring the changing degree of the logic of the signal. The result of judgment is inputted into the inner circuit of an integrated circuit as a signal 5 for an identified data/control signal. Therefore, the digital input signal 4 that is inputted through the outer input terminal 1 can be allocated to a data-signal processing circuit or a control-signal processing circuit on the basis of said signal in the inner circuit. The outer input terminal can be commonly used for the data signal input and the control signal input. Thus, the number of the outer input terminals can be reduced. Another output terminal 6 can be switched for inputting and outputting a data signal 8 or for inputting and outputting a control signal 9 by using the signal 5 for the identified data/control signal. Thus, the number of the outer terminals can be reduced in this way, too. |
