| 摘要 |
PURPOSE: An input circuit of a semiconductor device including many individual signature circuits connected parallel and an individual signature circuit are provided to supply an input circuit of a semiconductor device used in response to a high frequency interface and to supply a signature circuit used parallel with a wavelength clamp circuit. CONSTITUTION: An input circuit of a semiconductor device including many individual signature circuits connected parallel and an individual signature circuit include an input line(315), input buffers(300, 302, 304, 306) and individual signature circuits(311, 312, 313). The input line(315) sends the signal, which is permitted to the input steps, to the input buffers(300, 302, 304, 306). The individual signature circuits(311, 312, 313) are parallel formed between the input line and the external voltage(VSS) and are enabled by the control signals(SEL1, SEL2, SEL3). The terminal, which requests the interface of the low speed, is assigned as a low speed input buffer(300) and the terminal, which requests the interface of the high speed, is assigned as high speed input buffers(302, 304, 306).
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