发明名称 |
Method for characterizing interconnect timing characteristics using reference ring oscillator circuit |
摘要 |
A reference ring oscillator circuit (RROC) is used to determine timing characteristics of a test interconnect structure in an integrated circuit. The RROC includes an odd number of inverters coupled together in a ring manner and has defined test segments at which a test interconnect can be loaded. Reference timing characteristics of the unloaded RROC are determined according to a calibration method including the steps of: (a) directly measuring signal propagation delay through each segment of the RROC; (b) modeling each test segment using an RC tree type reference circuit model having reference elements; (c) simulating the reference circuit model to provide a functional relationship between two reference capacitors; (d) defining upper and lower bounds for propagation delay through the test segment in terms of the reference elements; (e) determining values for the reference capacitor elements; and (f) measuring a reference frequency of oscillation of the unloaded RROC.
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申请公布号 |
US5790479(A) |
申请公布日期 |
1998.08.04 |
申请号 |
US19960710465 |
申请日期 |
1996.09.17 |
申请人 |
XILINX, INC. |
发明人 |
CONN, ROBERT O. |
分类号 |
G01R27/04;G01R31/28;G01R31/30;G01R31/317;G01R31/3185;(IPC1-7):G04F8/00;G01R15/12 |
主分类号 |
G01R27/04 |
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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