摘要:
A system and computer program for verifying performance of an array by simulating operation of edge cells in a full array model reduces the computation time required for complete design verification. The edge cells of the array (or each subarray if the array is partitioned) are subjected to a timing simulation while the center cells of the array are logically disabled, but remain in the circuit model, providing proper loading. Additional cells are specified for simulation if calculations indicate a worst-case condition due to a non-edge cell. Wordline arrivals are observed to determine worst-case rows for selection. For write operations, the difference between the wordline edges and the data edges is used to locate any non-edge “outlier” cells. For read operations, the wordline delays are summed with the bitline delays determined from edge column data to locate any outliers.
摘要:
A method for verifying performance of an array by simulating operation of edge cells in a full array model reduces the computation time required for complete design verification. The edge cells of the array (or each subarray if the array is partitioned) are subjected to a timing simulation while the center cells of the array are logically disabled, but remain in the circuit model, providing proper loading. Additional cells are specified for simulation if calculations indicate a worst-case condition due to a non-edge cell. Wordline arrivals are observed to determine worst-case rows for selection. For write operations, the difference between the wordline edges and the data edges is used to locate any non-edge “outlier” cells. For read operations, the wordline delays are summed with the bitline delays determined from edge column data to locate any outliers.
摘要:
A system and computer program for verifying performance of an array by simulating operation of edge cells in a full array model reduces the computation time required for complete design verification. The edge cells of the array (or each subarray if the array is partitioned) are subjected to a timing simulation while the center cells of the array are logically disabled, but remain in the circuit model, providing proper loading. Additional cells are specified for simulation if calculations indicate a worst-case condition due to a non-edge cell. Wordline arrivals are observed to determine worst-case rows for selection. For write operations, the difference between the wordline edges and the data edges is used to locate any non-edge “outlier” cells. For read operations, the wordline delays are summed with the bitline delays determined from edge column data to locate any outliers.
摘要:
A data input latch and clocking method and apparatus for high performance SRAM in which an L1 data input latch is controlled by a logical combination of the normal local clock buffer clock signal and the local array clock buffer clock signal. This logical combination of clock signals minimizes the hold time of the L1 latch provides a fast cycle time in which the SRAM macro can process successive write instructions while avoiding early mode issues.
摘要:
A dynamic-static logical control element for signaling an interval between the end of a control signal and a logical evaluation provides a compact circuit for blocking the indication of a non-evaluated state of a dynamic logic gate until a control signal has ended. The control signal is connected to a precharge input of the control element and a summing node is connected to one or more evaluation trees and to the control element output via an inverter. The inverter is connected to an override circuit that forces the output of the control element to a state opposite the precharge state until the control signal has ended. The output of the control element then assumes a state corresponding to the precharge state until an evaluation occurs. The control element output thus produces a window signal indicating the interval between the end of the control signal and the evaluation.
摘要:
A bit-read apparatus includes a first decoder and N multiplexers, each having Q output nodes and Q pull-ups coupled thereto. Respective multiplexers have M selectors coupled to N×M respective select lines and register-file cells. The selectors are in Q groups coupled to respective output nodes. Each multiplexer has a logic gate with inputs coupled to respective multiplexer output nodes. A second decoder is coupled to an N+1th multiplexer having R output nodes and R pull-ups coupled thereto. The N+1th multiplexer also has N selectors, coupled to respective select lines of the second decoder and respective output logic gates of the N multiplexers. The N selectors are in R groups coupled to the R nodes. An output logic gate for N+1th multiplexer has R inputs coupled respectively to the R nodes. Each pull-up of the multiplexers drives its respective multiplexer output node responsive to an address-bit signal.
摘要:
A method and device are disclosed for the reduction of the penalty associated with inserting a latch in a circuit which is utilized to implement an integrated circuit in a data-processing system. A semiconductor device is disclosed which includes a main latch circuit, a feedback latch circuit and an output terminal. The main latch circuit is capable of receiving an input data signal and an input clock signal. The main latch circuit generates a latch output signal in response to the input data and clock signals. The feedback latch circuit is capable of receiving the latch output signal from the main latch circuit and storing the latch output signal. The feedback latch circuit is capable of generating a feedback latch circuit output signal which is received by the main latch circuit to maintain the latch output signal. The output terminal of the device is coupled to the feedback latch circuit for outputting a device output signal which is equal to the feedback latch circuit output signal.
摘要:
A method and apparatus is effective to preserve logic state potential levels in logic circuitry notwithstanding alpha particle collisions. Cross-coupled circuitry, including active devices, are implemented in a complementary logic circuit arrangement to hold current logic values in the event of a premature switching such as a switching that may be induced by alpha particle collision with the semiconductor logic circuit. Stabilizing transistor switching devices are arranged to sense an inappropriate or premature switching initiation and respond thereto by operating to maintain the appropriate logic levels within the logic circuitry. In one embodiment, the internal node of an upper circuit in a dual-rail logic circuit is connected to a gate terminal of a cross-coupled PFET device in the lower circuit. The cross-coupled PFET device is operable to sense an initiated untimely switching action in the upper circuit and effect a re-application of the holding PFET in the upper circuit to re-establish the appropriate logic potential levels in the upper circuit.
摘要:
An information handling system (IHS) includes a processor with on-chip or off-chip SRAM array. After a read operation, a control circuit may instruct the SRAM array to conduct a precharge operation, or alternatively, instruct the SRAM array to conduct an equalize bitline voltage operation. A read operation may follow the precharge operation or the equalize bitline voltage operation. The control circuit may instruct the SRAM array to conduct an equalize bitline voltage operation if an equalized voltage of a bitline pair exhibits more that a predetermined amount of voltage. Otherwise, the control circuit instructs the SRAM array to conduct a precharge operation before the next read operation.
摘要:
A method and apparatus for ensuring proper operation of a dynamic circuit is provided. A dynamic circuit instance has a plurality of outputs connected to a respective one of a plurality of leakage detector circuits. An output of each leakage detector circuit is connected with a respective one of a plurality of keeper circuits that reside at the dynamic circuit. Each of the plurality of keeper circuits has a unique size ratio with respect to a logic element size of the dynamic circuit.