摘要:
An apparatus and method provide logically controlled masking of one or more maskable data bits from a plurality of data bits that are input to a dynamic logic circuit. No masking logic and attendant delay penalty is coupled in the data path that is not needed for unmasked bits from the plurality of data bits that do not need masking. A system clock has a precharge phase and an evaluate phase. A first clock buffer is coupled to a precharge switch and precharges a dynamic node during the precharge phase. A second clock buffer having substantially the same delay from system clock input to an output of the second clock buffer is gated by a derivative of a mask. The output of the second clock buffer controls one or more switches in series with switches controlled by the maskable data bits.
摘要:
A method, an apparatus, and a computer program product are provided for flood mode implementation of SRAM cells that employ a continuous bitline local evaluation circuit. Flood mode testing is used to weed out marginal SRAM cells by stressing the SRAM cells. Flood mode is induced by beginning with a normal write operation. After new data values have been forced into the SRAM cells, then the write signal is chopped off. A delay block keeps the wordline signal at the high supply, and the SRAM cells go into flood mode. At this juncture marginal cells can be easily detected and later mapped to redundant cells.
摘要:
In a first aspect, a first method is provided for testing an integrated circuit (IC). The first method includes the steps of (1) selecting a bit from each of a plurality of memory arrays formed on an IC chip; (2) selecting one of the plurality of memory arrays; and (3) storing the selected bit from the selected memory array. Numerous other aspects are provided.
摘要:
A method and apparatus are provided for implementing power saving in a content addressable memory (CAM). A compare array is matched against a key and if a match occurs then logic coupled to the compare array generates a hit signal. A data array includes precharge circuitry and data output latches to capture the data output. A clock gate coupled to the logic provides clock signals to the output latches and precharge circuitry of the data array when a hit occurs. When a hit does not occur, the clock signals are gated off to the output latches and precharge circuitry of the data array.
摘要:
A glitch protect valid cell and method for maintaining a desired logic state value in response to a glitch signal and a timing signal. The glitch protect valid cell may be integrated with a content addressable memory (CAM) array for indicating whether word data stored within the CAM is valid. The glitch protect valid cell includes a memory element, a state machine, and a glitch protect circuit each responsive to one another. The glitch protect circuit includes a propagation delay assembly and a restore assembly electrically coupled to one another. The propagation delay assembly includes a first pull down network and a NOR gate electrically coupled to one another. The restore assembly includes a second pull down network electrically coupled to the propagation delay assembly. The first pull down network is responsive to the glitch signal and the timing signal to selectively engage the NOR gate. In a glitch protect condition, the glitch protect valid cell restores the initial logic state value of the true valid bit despite at least one glitch signal invalidating the initial value. As such, the first pull down network resets the initial state value of the true valid bit according to the timing signal and the glitch signal supplied to the glitch protect circuit. The initial state value of a true valid bit is restored in the memory element with the second pull down network via the timing signal and a restore signal provided by an enabled pull up network within the NOR gate. Specifically, the second pull down network is responsive to the pull up network selectively enabled within the NOR gate and resets the complement valid bit in the memory element to consequently restore the initial state value of the true valid bit.
摘要:
A method, an apparatus, and a computer program product are provided for flood mode implementation of SRAM cells that employ a continuous bitline local evaluation circuit. Flood mode testing is used to weed out marginal SRAM cells by stressing the SRAM cells. Flood mode is induced by beginning with a normal write operation. After new data values have been forced into the SRAM cells, then the write signal is chopped off. A delay block keeps the wordline signal at the high supply, and the SRAM cells go into flood mode. At this juncture marginal cells can be easily detected and later mapped to redundant cells.