Abstract: A memory with data array (e.g., L2 cache) addressable in rows and columns and techniques to access data therein are proposed. Unlike conventional data arrays, the proposed memory allows data access to be initiated based on a row (or set) address even though the column (or way) address is not yet available. When the column address is determined, it can be used to select the correct data. Since the data access is started prior to determining the column address, memory access latency is reduced.

Abstract: Virtualized scan chain testing in a random access memory array, and related methods and computer-readable media are disclosed. To facilitate virtualized scan chain testing, the memory array includes an integrated test circuit that causes the memory array to behave as a serialized scan chain. The integrated test circuit forces serialized write and read access to offset entries in the memory array on each scan cycle in a scan mode based on received serialized test data. After the number of scan cycles equals the number of entries the memory array, the entries in the memory array are fully initialized with test data from the serial test data flow. In subsequent scan cycles, the integrated test circuit continues to perform serial read operations to cause stored serial test data to be serially shifted out as an output serial data flow that then be compared to the original serial test data.

Abstract: Systems and methods relate to a matchline receiver of a content-addressable memory (CAM). A matchline of the CAM, which provides a hit/miss indication for a search operation of a data word is provided to the matchline receiver. The matchline receiver comprises a retention circuit to provide a hit/miss output, wherein the retention circuit retains, at the hit/miss output, the hit/miss indication provided by the matchline during a first clock phase of a clock, even if the hit/miss indication provided by the matchline is modified by a write operation or an invalidation operation during the first clock phase.

Abstract: This patent describes a method for varying the amplitude and frequency of power supply oscillations produced by content addressable memories or other critical circuits using BIST. Supply oscillations are produced by performing noisy (high switching activity—high current demand) searches followed by quiet (low switching activity—low current demand) searches. The amplitude and frequency of oscillations can be varied by changing the number of noisy and quiet searches e.g. pattern 1-noisy quiet, noisy, quiet; pattern 2-noisy, noisy, quiet, noisy, noisy, quiet, etc. By going through different patterns the current demand from the CAM macro increases the likelihood of producing worst—case noise and enables testing of CAM operation as well as surrounding circuitry in these noisy conditions.

Abstract: A method and structure for improving a content addressable memory array has a plurality of serially connected memory sub-arrays (which include at least one memory cell), a matchline connected to each of the sub-arrays, a valid memory cell, a comparator receiving input from the matchline and valid memory cell, a sinkline output from the comparator, and a precharge device. The sinkline and matchline are reset from a first voltage to a second voltage depending upon the results of a compare operation of the input data to the data in the storage device. When the second voltage appears on the matchline and the first voltage appears on the sinkline this indicates a match between the data within all of the sub-arrays and the input data.

Abstract: A method and structure for improving a content addressable memory array has a plurality of serially connected memory sub-arrays (which include at least one memory cell), a matchline connected to each of the sub-arrays, a valid memory cell, a comparator receiving input from the matchline and valid memory cell, a sinkline output from the comparator, and a precharge device. The sinkline and matchline are reset from a first voltage to a second voltage depending upon the results of a compare operation of the input data to the data in the storage device. When the second voltage appears on the matchline and the first voltage appears on the sinkline this indicates a match between the data within all of the sub-arrays and the input data. If the second voltage appears on the sinkline this indicates a mismatch between data within any of the sub-arrays and the input data, or an invalid status within the valid memory cell and maintains the sinkline at the second voltage.

Abstract: A method and structure for improving a content addressable memory array has a plurality of serially connected memory sub-arrays (which include at least one memory cell), a matchline connected to each of the sub-arrays, a valid memory cell, a comparator receiving input from the matchline and valid memory cell, a sinkline output from the comparator, and a precharge device. The sinkline and matchline are reset from a first voltage to a second voltage depending upon the results of a compare operation of the input data to the data in the storage device. When the second voltage appears on the matchline and the first voltage appears on the sinkline this indicates a match between the data within all of the sub-arrays and the input data.

Abstract: A method and structure for improving a content addressable memory array has a plurality of serially connected memory sub-arrays (which include at least one memory cell), a matchline connected to each of the sub-arrays, a valid memory cell, a comparator receiving input from the matchline and valid memory cell, a sinkline output from the comparator, and a precharge device. The sinkline and matchline are reset from a first voltage to a second voltage depending upon the results of a compare operation of the input data to the data in the storage device. When the second voltage appears on the matchline and the first voltage appears on the sinkline this indicates a match between the data within all of the sub-arrays and the input data. If the second voltage appears on the sinkline this indicates a mismatch between data within any of the sub-arrays and the input data, or an invalid status within the valid memory cell and maintains the sinkline at the second voltage.