发明名称 |
Circuit timing monitor having a selectable-path ring oscillator |
摘要 |
An in-circuit timing monitor having a selectable-path ring oscillator circuit provides delay and performance measurements in an actual circuit environment. A test mode signal is applied to a digital circuit to de-select a given functional input signal applied to a functional logic block within the digital circuit and replace it with feedback coupled from an output of the functional logic block, when test mode operation is selected. The signal path from the de-selected input to the output is selected so that the signal path will oscillate, and a characteristic frequency or phase of the output signal is measured to determine the delay. Other inputs to the functional logic block are set to a predetermined set of logic values. The selection may be made at a register preceding the digital inputs or made in the first level of logic of the functional logic block.
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申请公布号 |
US7810000(B2) |
申请公布日期 |
2010.10.05 |
申请号 |
US20060559436 |
申请日期 |
2006.11.14 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
NGO HUNG C.;CARPENTER GARY D.;DRAKE ALAN J.;KUANG JENTE B. |
分类号 |
G01R31/3181;G01R31/30 |
主分类号 |
G01R31/3181 |
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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