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Hung C. Ngo, Austin US

Hung C. Ngo, Austin, TX US

Patent application numberDescriptionPublished
20080201672CASCADED PASS-GATE TEST CIRCUIT WITH INTERPOSED SPLIT-OUTPUT DRIVE DEVICES - A cascaded pass-gate test circuit including interposed split-output drive devices provides accurate measurement of critical timing parameters of pass gates. The rise time and fall time of signals passed through the pass gate can be separately measured in a ring oscillator or one-shot delay line configuration. Inverters or other buffer circuits are provided as drive devices to couple the pass gates in cascade. The final complementary tree in each drive device is split so that the only one of the output pull-down transistor or pull-up transistor is connected to the next pass gate input, while the other transistor is connected to the output of the pass gate. The result is that the state transition associated with the device connected to the pass gate input is dominant in the delay, while the other state transition is propagated directly to the output of the pass gate, bypassing the pass gate.08-21-2008
20080265957Self-Resetting Phase Frequency Detector with Multiple Ranges of Clock Difference - A phase detector which provides a dynamic output signal and which automatically resets if a reference clock signal and a feedback clock signal align after an output pulse is generated. With the phase detector in accordance with the present invention, when there is a difference between the positive clock edges of the reference clock signal and the feedback clock signal, the phase detector generates output pulse. The output is used to correct the feedback clock signal. In the next cycle, if the feedback signal is corrected so that both the reference clock signal and feedback clock signal are aligned, then the output signals are reset to zero. The ability to reset advantageously prevents an unexpected correction that can occur in certain phase detector designs.10-30-2008
20080266000Digital Frequency Multiplier Circuit - A digital frequency multiplier circuit is disclosed. The digital frequency multiplier circuit includes a digitally controlled oscillator (DCO), a phase detector and a control circuit. The DCO generates an internal feedback signal. The phase detector detects a phase difference between the internal feedback signal and an external reference clock signal. Coupled between the phase detector and the DCO, the control circuit adjusts the DCO to align the internal feedback signal with the external reference clock signal after a phase difference between the internal feedback signal and the external reference clock signal has been detected. The control circuit also locks a modulation frequency of the DCO and monitors the state of the digital frequency multiplier circuit in order to maintain the lock.10-30-2008
20080267341High Performance, Low Power, Dynamically Latched Up/Down Counter - A high performance, low power up/down counter is set forth. The counter presented is controlled by two clock pulses, an up pulse and a down pulse, and updates all bits of the counter in parallel. These bits are then latched using a scannable pulsed limited output switching dynamic logic latch. By using a limited switch dynamic logic latch, the counter is able to utilize the speed of dynamic logic without requiring the traditional dynamic logic power. The area saved and speed gained by using a dynamic latch is significant compared to a typical edge-triggered flip-flop. Additionally, by computing all the next count state bits in parallel, the counter reduces an overall count computation delay by eliminating the counter ripple.10-30-2008
20090027065Wordline-To-Bitline Output Timing Ring Oscillator Circuit for Evaluating Storage Array Performance - A wordline-to-bitline timing ring oscillator circuit for evaluating storage cell access time provides data on internal bitline access timing, and in particular the total wordline select-to-bitline read output timing. Columns of a storage array are connected in a ring, forming a ring oscillator. The bitline read circuit output of each column is connected to a wordline select input of a next column, with a net inversion around the ring, so that a ring oscillator is formed. The period of oscillation of the ring oscillator is determined by the total wordline select-to-bitline read circuit output timing for a first phase and the pre-charge interval time for the other phase, with the bitline read timing dominating. The circuit may be applied both to small-signal storage arrays, with the sense amplifier timing included within the ring oscillator period, or to large-signal storage arrays, with the read evaluate circuit timing included.01-29-2009
20090177870Method and System for a Wiring-Efficient Permute Unit - A method of providing wiring efficiency in a permute unit. Multiple selectors receive input data and shared control signals from multiple register files. The permute unit includes multiple multiplexors (MUXs) coupled to multiple logical AND gates. The multiple logical AND gates are coupled to multiple logical OR gates. The logical AND gates are physically separated from the logical OR gates. The logical AND gates receive input from one or more output data signals from the selectors. The logical OR gates combine the one or more output signals from the logical AND gates and provide output data from the permute unit.07-09-2009
20090302354High Density Stable Static Random Access Memory - A memory circuit includes a plurality of bit line structures, a plurality of word line structures intersecting the plurality of bit line structures to form a plurality of cell locations; and a plurality of cells located at the plurality of cell locations. Each of the cells is selectively coupled to a corresponding one of the bit line structures under control of a corresponding one of the word line structures, and each of the cells in turn includes a logical storage element having at least a first n-type field effect transistor and at least a first p-type field effect transistor. The at least first n-type field effect transistor is formed with a relatively thick buried oxide layer sized to reduce capacitance of the bit line structures, and the at least first p-type field effect transistor is formed with a relatively thin buried oxide layer12-10-2009
20100218155Automated Critical Area Allocation in a Physical Synthesized Hierarchical Design - A method, computer program product, and data processing system for efficiently performing automated placement of timing-critical unit-level cells in a hierarchical integrated circuit design is disclosed. In preparation for global optimization the entire unit at the cell level, macro-level cells are assigned a “placement force” that serves to limit the movement of the macro-level cells from their current position. Movement boundaries for each macro element are also defined, so as to keep the components in a given macro element in relative proximity to each other.08-26-2010

Patent applications by Hung C. Ngo, Austin, TX US