Abstract: An apparatus and method for protecting a computer system from array reliability failures uses Array Built-In Self-Test logic along with code and hardware to delete cache lines or sets that are defective, identify corresponding fuse repair values, proactively call home if spare fuses are not available, schedule soft fuse repairs for the next system restart, schedule line deletes at the next restart, store delete and fuse repairs in a table (tagged with electronic serial id, timestamp of delete or ABIST fail event, address, and type of failure) and proactively call home if there were any missed deletes that were not logged. Fuse information can also be more permanently stored into hardware electronic fuses and/or EPROMs. During a restart, previous repairs are able to be applied to the machine so that ABIST will run successfully and previous deletes to be maintained with checking to allow some ABIST failures which are protected by the line deletes to pass.

Abstract: Memory array built in self testing utilizing including a simple data history table. The table is used to track failing locations observed during any level of assembly test of processor or logic semiconductor chips where the chips contain SRAM macros with redundant elements for failure relief.

Abstract: A decoder circuit includes a pulse powered stage having a plurality of fan-in inputs thereto, a dynamic stage fed by the pulse powered stage, and a replica node selectively coupled to an output node of the pulse powered stage by a pass device. The pass device and the dynamic stage are controlled by a clock signal so as to enable a self-timed evaluation of the pulse-powered stage with a clocked enablement of the dynamic stage. A pull up device restores the dynamic stage to a precharged condition, the pull up device controlled by a second clock signal independent of the first clock signal.

Abstract: A method and apparatus for providing flexible modular redundancy allocation for memory built in self test of random access memory with redundancy. The apparatus includes a first redundancy support register that includes inputs for receiving an address of a location in memory under test and data relating to must fix repair elements. The address includes a row and column vector of the location. The first redundancy support register also includes outputs for transmitting the address and data. The apparatus also includes a second redundancy support register including inputs for receiving the address and data from the outputs of the first redundancy support register. Each of the inputs of the second redundancy support register shares a one-to-one correspondence to each of the outputs of the first redundancy support register. The apparatus further includes allocation logic for providing a modular implementation of the first redundancy support register and the second redundancy support register.

Abstract: A method and apparatus for implementing ABIST data compression and serialization for memory built-in self test of SRAM with redundancy. The method includes providing detection signals asserted for one failing data out, two failing data outs, and greater than two failing data outs. The method also includes individually encoding the failing bit position of each corresponding failing data out with a binary representation value corresponding therewith. The method further includes serializing results of the providing detection signals and the individually encoding, and transmitting results of the serializing to a redundancy support register function on a single fail buss.

Abstract: The method described uses a Skip-Over technique which requires a set of muxes at the input and output of a block that is to be repaired. The improved method of implementing I/O redundancy control logic has a minimal impact to both chip area and chip wire tracks. To overcome problems of required real estate usage on a chip that was undesirable enables use of odd and even decoder outputs that can share a single wire track, the same wire being utilizable for both odd and even decoder outputs. In order to implement the decode and carry function as a centralized function, there arises a requirement that logically adjacent decode circuits (decoders connected by a carry signal) should be physically close together to minimize the overhead of the carry wiring. If the decode structure and the mux structure are arranged orthogonal to each other, then each decoder output would require a wire track. The described method however, allows odd and even decoder outputs to share the same wire track.