发明名称 |
Integrated circuit with clock generator circuit. |
摘要 |
<p>A microprocessor (10) or other integrated circuit including a clock generator circuit which is dependent on an externally-provided reference signal (XTALCLK) includes the capability of detecting the loss of this externally-provided reference signal and producing an alternate clock signal despite the loss of the reference. In a particular embodiment, the clock generator comprises a phase locked loop frequency synthesizer (23-27) which normally relies on an external crystal oscillator for its reference frequency signal. The generator includes a circuit (22) for detecting abnormalities in the crystal signal and switching the voltage controlled oscillator of the frequency synthesizer to an internally-generated reference voltage. In the particular embodiment, the clock generator is also capable of producing a reset signal in response to the loss of the reference signal.</p> |
申请公布号 |
EP0355466(A2) |
申请公布日期 |
1990.02.28 |
申请号 |
EP19890113871 |
申请日期 |
1989.07.27 |
申请人 |
MOTOROLA, INC. |
发明人 |
MCDERMOTT, MARK W.;FOURCROY, ANTONE L. |
分类号 |
G01R29/027;G06F1/04;H03L7/14 |
主分类号 |
G01R29/027 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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