Abstract: A memory system includes a memory that provides digital data and a built-in self-test (BIST) circuit for testing the memory for determining defective storage units of the memory. The memory system has a data output for providing data from the memory to an external system. The data output of the memory system has a first bit width. The memory has a data output that has a second bit width that is greater than the first bit width. The BIST circuit has a data input that is of the second bit width.

Abstract: A system for controlling the refresh cycles of a DRAM cell array based upon a temperature measurement. During active mode, a refresh request indication based on a measured temperature is provided to a DRAM controller (e.g. of another integrated circuit die), wherein the DRAM controller initiates a refresh cycle of the DRAM cell array in response thereto. In a self refreshing mode, the DRAM controller does not initiate refresh cycles, but refresh cycles are performed by a controller on the integrated circuit die of the array based upon a temperature measurement.

Abstract: A non-volatile memory system (230) includes a magnetoresistive random access memory (MRAM) (232) including a plurality of magnetoresistive memory cells, a floating-gate nonvolatile memory (234) including a plurality of floating-gate memory cells, and a controller (236) coupled to the MRAM (232) and to the floating-gate nonvolatile memory (234). The controller (236) is adapted to be coupled to a system bus (220) and controls a selected one of the MRAM (232) and the floating-gate nonvolatile memory (234) in response to an access initiated from the system bus (220).

Abstract: A system for controlling the refresh cycles of a DRAM cell array based upon a temperature measurement. During active mode, a refresh request indication based on a measured temperature is provided to a DRAM controller (e.g. of another integrated circuit die), wherein the DRAM controller initiates a refresh cycle of the DRAM cell array in response thereto. In a self refreshing mode, the DRAM controller does not initiate refresh cycles, but refresh cycles are performed by a controller on the integrated circuit die of the array based upon a temperature measurement.

Abstract: Storage circuitry (66) may be used to store the values of fuses (77) so that storage circuitry (66) can be read instead of fuses (77). By accessing the fuse values from storage circuitry (66) rather than from fuses (77), there will be no sense current to fuses (77) that may cause marginal fuse blowage for fuses that have not yet been blown. This helps to prevent the situation in which an unblown fuse is erroneously read as having been blown. The use of storage circuitry (66) thus significantly improves the reliability of fuse module (20). For some embodiments, selection storage circuitry (64) may be used to determine whether storage circuitry (66) may be read or whether one of fuses (77) must be read in order to retrieve the desired current fuse value. The fuse value stored in storage circuitry (66) can also be used as direct hardware signals (80).

Abstract: A memory not only uses redundant cells but also redundant references to reduce the likelihood of a failure. In one approach a failure in a reference can cause both the primary cell as well as the redundant cell to be ineffective. To overcome this potential problem two references for each bit are employed. In one form, the primary cell of a first bit is compared to one reference and the redundant cell of the first bit is compared to another reference. The primary and redundant cell of a second bit can use these two references as well. In another aspect, two references are placed in parallel for both the primary and redundant cell of the bit.

Abstract: Leakage current is eliminated in a memory array during a low power mode of a processing system having a processor that interfaces with the memory array. Because two power planes are created, the processor may continue executing instructions using a system memory while bypassing the memory array when the array is powered down. A switch selectively removes electrical connectivity to a supply voltage terminal in response to either processor-initiated control resulting from execution of an instruction or from a source originating in the system somewhere else than the processor. Upon restoration of power to the memory array, data may or may not need to be marked as unusable depending upon which of the two power planes supporting arrays to the memory array are located. Predetermined criteria may be used to control the timing of the restoration of power. Multiple arrays may be implemented to independently reduce leakage current.

Abstract: A processing system comprising at least one processing unit, a plurality of I/O devices, and a central interrupt control unit intercoupling the processing unit and the plurality of I/O devices. The central interrupt control unit is configured to receive interrupt signals from the I/O devices and is configured to distribute said interrupt signals to the processing unit. The central interrupt control unit is further configured to provide a signal simulative of an interrupt signal to simplify the testing process.