Abstract: The reliable capture of data from a DDR-2 memory device can be provided using timing signals provided by the DDR-2 memory device in conjunction with enable signals generated there from. The reliable capture of data from the DDR-2 DRAM can be used to extend the data valid window for which the captured data is provided to a system that is in communication with the memory controller. Extending the data valid window can enable the generation of a data valid strobe signal (that is synchronous with a system clock used to operate the system), which satisfies all timing requirements associated with interfacing the DDR-2 memory device to the system over a wide variation of process, voltage, and temperature.

Abstract: A DRAM interface circuit includes a clock generation circuit configured to generate a plurality of internal clock signals and skew data in response to a plurality of data strobe signals (DQS) received at an interface of the integrated circuit device. A data capture circuit is also provided. The data capture circuit is configured to capture a plurality of data streams (DQ) associated with the plurality of data strobe signals in a manner that sufficiently reduces skew between the captured data streams so that all of the plurality of data streams may then be reliably captured in-sync with a common clock.

Abstract: A level shifter is presented that allows fast switching while requiring low power. In accordance with some embodiments of the invention, the level shifter is a two stage level shifting circuit with p-channel and n-channel transistors biased so as to limit the potential between the source to gate or drain to gate of any of the transistors. Pull-up transistors are placed in a transition state so that spikes resulting from an increasing or decreasing input voltage turn on or off the pull up transistors to assist in the switching.

Abstract: A method and apparatus for source synchronous testing have been disclosed. In one case a data signal is delayed and a selectively activated delay is applied to a clock. This allows the clock to be positioned before the data and also after the data.

Abstract: A process for forming CMOS devices is disclosed in which disposable spacers are used to obtain a structure having improved gap-fill characteristics. First, gate film stacks are formed on the substrate. A shallow implant process is performed so as to form shallow source/drain implant regions. A layer of oxide and a layer of silicon nitride are deposited and etched to form a first set of spacers that extend on opposite sides of the gate film stacks. A second implant is performed so as to form intermediate source/drain implant regions. A set of disposable spacers are then formed that extend on opposite sides of each of the gate film stacks. A third implant process is performed so as to form deep source/drain implant regions. The disposable spacers are then removed, providing more space for the subsequently-formed contact to land.

Abstract: A method and apparatus for a CAM with reduced cross-coupling interference have been disclosed.

Abstract: A clock generator generates multiple clock signals based on an input signal and adjusts the phases of the clock signals relative to a phase of the input signal, based on a control signal. The clock generator includes a phase locked loop that includes a phase shift unit. The phase shift unit selects some of the clock signals based on the control signal and generates a feedback signal based on the selected clock signals. The feedback signal has a phase based on the phases of the selected clock signals. The phase locked loop aligns the phase of the feedback signal with the phase of the input signal. In this process, the phase locked loop shifts the phase of each of the clock signals relative to the phase of the input signal.

Abstract: A method for testing memory in an integrated circuit device is disclosed. The method includes executing a test routine in a portion of the memory at a speed sufficient to fully test the memory cells, identifying faulty memory cells in the tested portion of the memory; writing an error map in another portion of the memory, the error map indicating the location of faulty memory cells found in the tested portion and, after executing the test routine and writing the error map, repairing at least some of the faulty memory cells using the error map. Once one portion of memory is tested, another portion is tested and a prior tested portion is used to write a new error map. Repairing, by analyzing the error map, is done at a slower speed than required for memory testing, allowing the use of a smaller logic section in the integrated circuit.

Abstract: In a multi-queue memory system, a plurality of read count pointers (one for each queue) are stored in a read address file, and used to generate empty flags. A read count pointer associated with a first queue is retrieved from the read address file, and it is determined whether the first queue should be available for a re-read operation. If so, the retrieved read count pointer is stored as a first read mark value. The read count pointer is incremented in response to each read operation performed from the first queue, thereby creating an adjusted read count pointer. If a re-read operation is to be performed from the first queue, the first read mark value is stored in the read address file. Otherwise, the adjusted first read count pointer is stored in the read address file. Similar operations are performed on the write side of the multi-queue memory system.

Abstract: A method and apparatus for a CAM with reduced cross-coupling interference have been disclosed.

Abstract: Electrostatic discharge and electrical overstress protection circuit is disclosed to include a discharging circuit, a detection circuit and a controller. The controller is operable to sense and compare the output voltage from the detection circuit to a reference voltage. The controller, upon detection of a normal operating condition or an electrical overstress (EOS) situation, is operable to cause the discharging circuit to discharge any excess voltage from the voltage supply to the electrical ground at a safety voltage level. The controller, upon detection of an electrostatic discharge (ESD) event, is operable to cause the discharging circuit to discharge the excess voltage at a second voltage level that is less than the safety voltage level.

Abstract: An ESD protection circuit for over-voltage signal bus is disclosed that includes a diode circuit that is electrically connected to a pseudo power supply circuit. The pseudo power supply circuit includes a pseudo first power supply line coupling to an actual first power supply line having a first voltage supply level and a pseudo second power supply line coupling to an actual second power supply line having a second voltage supply level. The pseudo first power supply line and the pseudo second power supply line are clamped by an ESD clamping circuit such that the ESD protection circuit discharges voltage when an ESD event occurs, and does not interfere with the internal circuit when an over-voltage occurs.

Abstract: Systems and methods of chip design and package implementation for attenuating noise in timing circuits, including phase-locked-loops (PLL) and delay-locked-loops (DLL), are disclosed. Embodiments of the present invention attenuate coupled noise, such as the effects of ground current surges, or power supply noise coupling through electro-static discharge (ESD) structures. In known systems, the ground supplies for the timing circuits are designed with power and ground supplies, separate from the core power and ground; although the ground supplies are connected via common VSSsubstrate, they are separated from pad ring output driver power and ground supplies. In embodiments of the present invention, the PLL or DLL and core supplies are kept separate from the output driver power and ground supplies, providing for improved systems and methods that attenuate the effects of ground current surges from chip output drivers as they switch from logic highs to logic lows.

Abstract: A multi-port serial buffer having a plurality of queues is configured to include a first set of queues assigned to store write data associated with a first port, and a second set of queues assigned to store write data associated with a second port. The available queues are user-assignable to either the first set or the second set. Write operations to the first set of queues can be performed in parallel with write operations to the second programmable set of queues. In addition, a first predetermined set of queues is assigned to the first port for read operations, and a second predetermined set of queues is assigned to the second port for read operations. Data can be read from the first predetermined set of queues to the first port at the same time that data is read from the second predetermined set of queues to the second port.

Abstract: A serial buffer having a plurality of virtual queues, which can be allocated to include various combinations of on-chip dual-port memory blocks, on-chip internal memory blocks and/or off-chip external memory blocks. The virtual queues are allocated and accessed in response to configuration bits and size bits stored on the serial buffer. Relatively large external memory blocks can be allocated to virtual queues used for data intensive operations, while relatively small and fast dual-port memory blocks can advantageously be allocated to virtual queues used for passing command and status information. The serial buffer provides an efficient and flexible manner for utilizing available memory, which not only minimizes the access latency but also provides a large amount of buffer space to meet different application needs.

Abstract: A synchronous memory system configurable in a multiplexed or non-multiplexed mode. In the multiplexed mode, address and data are provided on a shared bus, and accesses to the memory system are qualified by memory access control signals, including an address strobe signal, a counter enable signal and a counter repeat signal. A read/write control signal is maintained for one cycle after the last valid access command to avoid bus turn-around problems. In the multiplexed mode, chip enable and output enable signals may be constantly activated, thereby simplifying associated printed circuit board design. Different ports of the synchronous memory system can be independently configured to operate in either the multiplexed or non-multiplexed mode.

Abstract: A serial buffer is configured to transmit a plurality of received data packets through a data packet transfer path to a host processor. A doorbell controller of the serial buffer monitors the number of data packets transmitted to the host processor through the data packet transfer path, and estimates the number of data packets actually received by the host processor. The doorbell controller generates a doorbell command each time that the estimated number of data packets corresponds with a fixed number of data packets in a frame. The doorbell commands are transmitted to the host processor on a doorbell command path, which is faster than the data packet transfer path. The doorbell controller may estimate the number of data packets actually received by the host processor in response to a first delay value, which represents how much faster the doorbell command path is than the data packet transfer path.

Abstract: A system and method for using a doorbell command to allow sRIO devices to operate as bus masters to retrieve data packets stored in a serial buffer, without requiring the SRIO devices to specify the sizes of the data packets. The serial buffer includes a plurality of queues that store data packets. A doorbell frame request packet identifies the queue to be accessed within the serial buffer, but does not specify the size of the data packet(s) to be retrieved. Upon detecting a doorbell frame request packet, the serial buffer operates as a bus master to transfer the requested data packets out of the selected queue. The selected queue can be configured to operate in a flush mode or a non-flush mode. The serial buffer may also indicate that a received doorbell frame request has attempted to access an empty queue.

Abstract: An integrated circuit device includes a data input configured to receive a data signal and a clock input configured to receive a clock signal associated with the data signal. The device further includes a sample timing circuit coupled to the clock input and the data input and configured to generate a statistical measure of timing of the data signal and to identify a sample timing for the data signal based on the generated statistical measure. The sample timing circuit may be configured to generate samples of the data signal at a rate higher than a rate of the clock signal, and to generate the statistical measure of timing of the data signal from the data signal samples.

Abstract: A method and apparatus for logical identification priority have been disclosed.