| 摘要 |
The present invention includes a variable delay element that can be programmed by a combination of control signals whose values may be determined by a matrix of programming elements, preferably fuses. In a TEST mode, a multiplexer array decouples the matrix, and instead couples a combination of user provided TEST mode control signals to the variable delay element. TEST mode permits selection of a suitable delay by observing the effect on IC functionality of all available values of delay provided by these TEST mode user-provided control signals. Once a suitable delay has been determined, the matrix may be programmably altered to permanently store and provide to the variable delay element the appropriate pattern of control signals to produce such delay.
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