Abstract: A memory circuit includes a plurality of memory cells, each of the memory cells being operative to store multiple bits of data therein, and a plurality of column lines and row lines coupled to the memory cells for selectively accessing the memory cells. The circuit further includes multiple sense amplifiers, each of the sense amplifiers being connected to a corresponding one of the column lines and being operative to detect an electric charge stored in a selected one of the memory cells coupled to the corresponding column line and to generate an analog signal indicative of the stored electric charge. An analog multiplexer is connected to the sense amplifiers. The analog multiplexer is operative to receive the respective analog signals from the sense amplifiers and to generate an analog output signal having a magnitude which varies in time as a function of the respective analog signals from the sense amplifiers.

Abstract: A technique to reduce refresh power in a DRAM. In one embodiment, all of the DRAM memory cells are refreshed at a first rate and a subset of the memory cells are refreshed a second rate greater than the first rate. In another embodiment, the DRAM has a refresh controller that generates a refresh address and controls the refresh of the memory cells addressed by the refresh address. A marker memory is used by the refresh controller to determine which of the memory cells requires refreshing at a rate faster than the refresh rate of the remaining memory cells. Testing the DRAM uses a method to determine which of the memory cells are to be refreshed at the faster rate and to store the results in the marker memory.

Abstract: A memory device comprises a memory array and error correction circuitry coupled to the memory array. The memory device is configured to perform at least a partial word write operation and a read operation, with the partial word write operation comprising a read phase and a write phase. The write phase of the partial word write operation occurs in the same clock cycle of the memory device as the read operation by, for example, time multiplexing bitlines of the memory array within the clock cycle between the write phase of the partial word write operation and the read operation. Thus, the partial word write operation appears to a higher-level system incorporating or otherwise utilizing the memory device as if that operation requires only a single clock cycle of the memory device.

Abstract: Generally, methods and apparatus are provided for idle cycle refresh request in a dynamic random access memory. According to one aspect of the invention, a dynamic random access memory is refreshed by determining if a refresh of the dynamic random access memory is required; and allocating an idle cycle sequence to refresh at least a portion of the dynamic random access memory only if the determining step determines that a refresh of the dynamic random access memory is required. A refresh flag can optionally be set if a refresh is required. The idle cycle sequence comprises one or more idle cycles. The idle cycle sequence can optionally be allocated within a predefined duration of the refresh flag being set. The step of determining step whether a refresh of the dynamic random access memory is required can be based on real-time or expected conditions.

Abstract: A memory circuit includes a plurality of memory cells, each of the memory cells being operative to store multiple bits of data therein, and a plurality of column lines and row lines coupled to the memory cells for selectively accessing the memory cells. The circuit further includes multiple sense amplifiers, each of the sense amplifiers being connected to a corresponding one of the column lines and being operative to detect an electric charge stored in a selected one of the memory cells coupled to the corresponding column line and to generate an analog signal indicative of the stored electric charge. An analog multiplexer is connected to the sense amplifiers. The analog multiplexer is operative to receive the respective analog signals from the sense amplifiers and to generate an analog output signal having a magnitude which varies in time as a function of the respective analog signals from the sense amplifiers.

Abstract: A technique to reduce refresh power in a DRAM is disclosed. In one embodiment, all of the DRAM memory cells are refreshed at a first rate and a subset of the memory cells are refreshed a second rate greater than the first rate. In another embodiment, the DRAM has a refresh controller that generates a refresh address and controls the refresh of the memory cells addressed by the refresh address. A marker memory is used by the refresh controller to determine which of the memory cells requires refreshing at a rate faster than the refresh rate of the remaining memory cells. Also disclosed is a method to determine which of the memory cells are to be refreshed at the faster rate and to store the results in the marker memory.

Abstract: A dual-port memory circuit includes a plurality of memory sub-blocks. Each of the memory sub-blocks includes a plurality of single-port memory cells, at least one row line, and at least one local bit line, the row line and the bit line being coupled to the memory cells for selectively accessing the memory cells. The memory circuit further includes at least one global bit line connected to the plurality of memory sub-blocks. The global bit line is time-multiplexed during a given memory cycle such that the global bit line propagates data associated with a first port in the memory circuit during a first portion of the memory cycle, and the global bit line propagates data associated with a second port in the memory circuit during a second portion of the memory cycle.

Abstract: Generally, methods and apparatus are provided for idle cycle refresh request in a dynamic random access memory. According to one aspect of the invention, a dynamic random access memory is refreshed by determining if a refresh of the dynamic random access memory is required; and allocating an idle cycle sequence to refresh at least a portion of the dynamic random access memory only if the determining step determines that a refresh of the dynamic random access memory is required. A refresh flag can optionally be set if a refresh is required. The idle cycle sequence comprises one or more idle cycles. The idle cycle sequence can optionally be allocated within a predefined duration of the refresh flag being set. The step of determining step whether a refresh of the dynamic random access memory is required can be based on real-time or expected conditions.

Abstract: A dual-port memory circuit includes a plurality of memory sub-blocks. Each of the memory sub-blocks includes a plurality of single-port memory cells, at least one row line, and at least one local bit line, the row line and the bit line being coupled to the memory cells for selectively accessing the memory cells. The memory circuit further includes at least one global bit line connected to the plurality of memory sub-blocks. The global bit line is time-multiplexed during a given memory cycle such that the global bit line propagates data associated with a first port in the memory circuit during a first portion of the memory cycle, and the global bit line propagates data associated with a second port in the memory circuit during a second portion of the memory cycle.

Abstract: A memory device comprises a memory array and error correction circuitry coupled to the memory array. The memory device is configured to perform a partial word write operation in which an error correction code encode process for the given retrieved word is initiated prior to completion of an error correction code decode process for the given retrieved word based on an assumption that the error correction code decode process will not indicate an error in the given retrieved word. If the error correction code decode process when completed indicates an error in the given retrieved word, the error in the given retrieved word is corrected in the error correction circuitry, and the error correction code encode process is restarted using the corrected word. The error correction code decode process and an associated correct process are thereby removed from a critical timing path of the partial word write operation.

Abstract: One time programmable memory devices are disclosed that are programmed using hot carrier induced degradation to alter one or more transistors characteristics. A one time programmable memory device is comprised of an array of transistors. Transistors in the array are selectively programmed using hot carrier induced changes in one or more transistor characteristics, such as changes to the saturation current, threshold voltage or both, of the transistors. The changes to the transistor characteristics are achieved in a similar manner to known hot carrier transistor aging principles. The disclosed one time programmable memory devices are small and programmable at low voltages and small current.

Abstract: A memory self-testing system, apparatus, and method are provided which allow for testing for a plurality of bit errors and passing memory arrays having an error level which is correctable using selected error correction coding. An exemplary system embodiment includes a memory array, a comparator, an integrator, and a test control circuit. The memory array is adapted to store input test data and output stored test data during a plurality of memory read and write test operations. The comparator compares the input test data and the stored test data for a plurality of bit positions, and provides a corresponding error signal when the stored test data is not identical to the input test data for each bit position of the plurality of bit positions. The integrator receives the corresponding error signal and maintains the corresponding error signal for each bit position during the plurality of test operations.

Abstract: A method and apparatus for opening a fuse formed on a semiconductor substrate. The apparatus comprises a thyristor formed from CMOS device regions and having a one or two control terminals for permitting current to flow through the thyristor into the fuse, for opening the fuse.

Abstract: A method and apparatus are provided for reducing leakage current in a read only memory device. Leakage current is reduced by applying a biased gate voltage (relative to a source voltage) to the gate of at least one of transistor in the array. The biased gate voltage is applied at least during a precharge phase of a read cycle. When the array transistors are n-channel transistors, the biased voltage is a negative bias voltage (relative to the source voltage). When the array transistors are p-channel transistors, the biased voltage is a positive bias voltage (relative to the source voltage). Applying a negative backgate bias to the transistor's p-well contact can also reduce n-channel transistor subthreshold leakage current. Thus, for an n-channel array, a negative gate voltage and backgate bias (optional) are applied to cell transistors in the off state.

Abstract: A method and apparatus for opening a fuse formed on a semiconductor substrate. The apparatus comprises a thyristor formed from CMOS device regions and having a one or two control terminals for permitting current to flow through the thyristor into the fuse, for opening the fuse.

Abstract: A digit signal processor capable of operating at 100 MHZ with a 1.0 volt power supply. The digital signal processor is fabricated by application of strong phase-shift lithography to obtain a 0.12 &mgr;m gate dimension. A dual-mask process is utilized to improve resolution thereby producing high speed, low-voltage processors. A n+/p+ dual-Poly:Si module, and dopant penetration suppression techniques may be utilized.

Abstract: A single-poly flash memory cell has a control device, a switch device, and an erase device, all of which share a common polysilicon floating gate which is designed to retain charge in the programmed memory cell. The memory cell is erased by applying an erase voltage to the tub of the erase device to cause tunneling across the oxide layer separating the floating gate from the rest of the erase device structure. Since a typical tub-to-source/drain breakdown voltage (e.g., 15 volts) is greater than a typical erase voltage (e.g., 10 volts), the memory cell can be safely erased without risking the junction breakdowns that are associated with other prior art single-poly memory cell designs for deep sub-micron technologies (e.g., 0.25-micron and lower).

Abstract: An on-chip processor is used as a controller for burn-in and endurance testing of embedded non-volatile memory. An automated test machine downloads a test program into the non-volatile memory. The downloaded program contains a test program to be run on the non-volatile memory. When the burn-in or endurance test equipment activates the processor, the processor executes the program and performs a test on the non-volatile memory. The same method can be utilized to perform either the burn-in or endurance tests. Only the clock and reset lines are required to operate the test. Since the clock and reset lines are part of the processor's standard inputs, the method performs burn-in and endurance testing of an embedded non-volatile memory without bringing out the memory's address, data and control lines to the package pins of the integrated circuit.