Abstract The present invention provides an apparatus and method for repairing or improving the behavior of a tunable circuit of an integrated circuit (IC) when a target parameter exceeds a predetermined range due to a design and/or fabrication problem. The tunable circuit includes one or more tuning controllers for tuning a corresponding number of target circuits. Each tuning controller includes one or more registers and an optional decoder. Each target circuit includes a tunable portion and a functional portion. The functional portion can have one or more of a wide variety of functions including but not limited to logical gates, buffers, signal generators and amplifiers. The selectable parameters of the tunable circuit include timing delays, trip voltages, rise/fall times and/or output impedances. When a circuit designer wishes to tune the target parameter, an appropriate tuning pattern is latched into registers of the tuning controller. In turn, the tuning controller generates corresponding tuning pattern signals enabling target circuit(s) to changeably tune the target parameter by selectively enabling different tunable portions of the target circuit. For example, by selecting the appropriate load resistance and/or capacitance of the tunable circuit, the rise/fall time of the target circuit is tuned for compatibility with respect to the other portions of the IC or system. The tunable circuit of the present invention advantageously lends itself to post-fabrication correction of design or fabrication problems, thereby increasing the potential yield rate. In addition, the tunable circuit can be tested under different operating conditions in a non-destructive manner without the need for another time-consuming and costly IC fabrication cycle. Other advantages include the ability to selectively operate target circuit(s) of the IC at a higher speed under ideal conditions and at a lower speed under hostile conditions.
A tuning controller useful in tuning a target circuit of an integrated circuit (IC), which has at least one target parameter functioning outside of a proper operating range of values due to the IC fabrication process comprising: a decoder for generating a tuning signal from a tuning pattern provided to said decoder; a storage element coupled to said target circuit configured to receive said tuning signal and hold said tuning signal while said target circuit operates; a tunable portion coupled to said storage element configured to receive said tuning signal and generate a desired circuit parameter to modify said tunable portion; and a functional portion coupled to said tunable portion which generates target parameters within the proper operating range of values when said tunable portion is modified.
Claim 2
Dependent Claim
127 words
A tuning controller useful in tuning a target circuit of an integrated circuit (IC), which has at least one target parameter functioning outside of a proper operating range of values due to the IC fabrication process comprising: a decoder for generating a tuning signal from a tuning pattern provided to said decoder; a storage element coupled to said target circuit configured to receive said tuning signal and hold said tuning signal while said target circuit operates; a tunable portion coupled to said storage element configured to receive said tuning signal and generate a desired circuit parameter to modify said tunable portion; and a functional portion coupled to said tunable portion which generates target parameters within the proper operating range of values when said tunable portion is modified.
Claim 3
Dependent Claim
14 words
The tuning controller of claim 1 wherein said target parameter is a rise/fall time.
Claim 4
Dependent Claim
14 words
The tuning controller of claim 1 wherein said target parameter is a power consumption.