Abstract: Methods and systems for producing random numbers include a random number generator with a first port and a second port. The first port is configured to receive a first type of random data request, and the random number generator is configured to generate first random data while the first type of request is asserted on the first port. The second port is configured to receive a second type of random data request, and the random number generator is configured to generate only a specified length of second random data in response to receiving the second type of request on the second port. An embodiment of a system also includes a data structure configured to store multiple random values, which are derived from the first random data generated by the random number generator in response to the first type of random data request.

Abstract: Embodiments of methods and systems for producing random values include a first module that provides a random data request (e.g., a request for an unspecified length of random data) to a random number generator. The random number generator generates random data in response to the random data request, and multiple random values derived from the random data are stored in a buffer. In response to receiving a request for a random value (e.g., an initialization vector), the first module produces the random value based on the multiple random values stored in the buffer. The system also may be configured to receive requests for other types of random values, and to fulfill those requests using random data that is not buffered (e.g., random data that is received directly from the random number generator in response to a request for a specified length of random data).

Abstract: Apparatus and methods are provided for utilizing a plurality of processing units. A method comprises selecting a pending job from a plurality of unassigned jobs based on a plurality of assigned jobs for the plurality of processing units and assigning the pending job to a first processing unit. Each assigned job is associated with a respective processing unit, wherein the pending job is associated with a first segment of information that corresponds to a second segment of information for a first assigned job. The method further comprises obtaining the second segment of information that corresponds to the first segment of information from the respective processing unit associated with the first assigned job, resulting in an obtained segment of information and performing, by the first processing unit, the pending job based at least in part on the obtained segment of information.

Abstract: A system and method for bit eye center determination is provided. In general, the system samples an incoming data stream to determine where transitions in the data stream occur, selectively offsets the selected samples based on state criteria and the number of transitions in each set of samples, accumulates the offset samples and averages the result to determine the center of the bit eye. The system and method also provides the ability to locate the eye center even in the case of noise in the system, whether the noise is random or deterministic, including odd/even noise.

Abstract: A result value, such as a parity value, for a set of corresponding data elements from a plurality of storage devices is determined using a commutative operation. When accessing the set of corresponding data elements from a plurality of storage devices, a dual access can be performed for the storage device accessed last for the set of corresponding data elements so as to also obtain a data element from the last-accessed storage device for the next parity calculation. As a result, the number of storage device accesses can be reduced compared to conventional systems whereby a single access is performed for each storage device to obtain a single data element from the storage device.

Abstract: Apparatus and methods are provided for utilizing a plurality of processing units. A method comprises selecting a pending job from a plurality of unassigned jobs based on a plurality of assigned jobs for the plurality of processing units and assigning the pending job to a first processing unit. Each assigned job is associated with a respective processing unit, wherein the pending job is associated with a first segment of information that corresponds to a second segment of information for a first assigned job. The method further comprises obtaining the second segment of information that corresponds to the first segment of information from the respective processing unit associated with the first assigned job, resulting in an obtained segment of information and performing, by the first processing unit, the pending job based at least in part on the obtained segment of information.

Abstract: A system and method is provided for bit eye center retraining. In general, the system samples an incoming data stream to determine where transitions in the data stream occur, selectively compares the location of the transitions to the expected locations to produce difference values, and combines pairs of difference values to determine when the sample point of the data stream needs to be adjusted.

Abstract: A result value, such as a parity value, for a set of corresponding data elements from a plurality of storage devices is determined using a commutative operation. When accessing the set of corresponding data elements from a plurality of storage devices, a dual access can be performed for the storage device accessed last for the set of corresponding data elements so as to also obtain a data element from the last-accessed storage device for the next parity calculation. As a result, the number of storage device accesses can be reduced compared to conventional systems whereby a single access is performed for each storage device to obtain a single data element from the storage device.

Abstract: A method for aligning parallel path data bit streams that may contain skewed data between bit streams and an integrated circuit are disclosed. The method includes, for each bit stream, sampling P data presented on a positive edge of a clock, sampling N data presented on a negative edge of the clock, and delaying the sampled P and N data by one of zero, one-half, one, or other multiple of one-half clock cycle. Delaying the sampled P and N data by one of zero, one-half, one, or other multiple of one-half clock cycle is selected to remove any skew and aligns the sampled P and N data between bit streams.

Abstract: A plurality of serially coupled circuit cells (12-20) are modeled as a distributed serial load. The distributed serial load provides an accurate load model in situations where one cell is effected by loading on subsequent circuit cells, i.e. downstream loading is conveyed back to the first cell. The capacitance (22) and resistance (24, of each cell has a loading effect on each previous cell. The effective resistance and capacitive values of each cell is identified and maintained as one element of the distributed serial load model. The distributed serial load accurately models the loading of unbuffered cells (16-20). The distributed serial load is also applicable to portions of circuit cells (38,40) that are not be buffered and where the downstream loading has an effect on previous circuit drivers (14).

Abstract: An electronic key validation process increases security by encrypting the security access codes. A key (10) receives data having a hidden polynomial select code and polynomial seed from a host (12). A locally stored (24, 26) select offset and seed offset in the key identifies the location (22) of the select code and seed in the data. The select code decodes (32) into polynomial coefficients which are used to configure a polynomial generator (34). The seed is loaded into the polynomial generator as a starting point of the polynomial. The polynomial generator is clocked a number of cycles to calculate a remainder. The select code is modified (28) to select a new polynomial, and the polynomial generator is clocked another number of cycles. The host runs a similar encryption algorithm. The remainder is sent to the host where it is compared with the host generated remainder for key validation.

Abstract: A low power flip-flop circuit is disclosed including a clocked flip-flop (10) and switching circuit (40, 60) with control inputs coupled to the data input and data output of the flip-flop to determine whether or not the data input to the flip-flop is changing. Any clock pulse during periods when the data input is not changing consumes power without providing a useful function. The switching circuit passes clock pulses to a clock input of the flip-flop only when new data is present to be latched into the flip-flop, i.e. data input state and data output state disagree. The switching circuit blocks clock pulses to the flip-flop when the data to the flip-flop is not changing and thereby saves power consumption.

Abstract: A method for determining test pattern fault equivalence. The method comprises selecting a bridging fault (16) from a digital circuit, then determining a stuck-at fault (17) which guarantees detection of the bridging fault. Generation of a test vector (18) which detects the stuck-at fault. Simulating the test vector (19) to find all bridging faults that are detected by the test vector, and repeating the above steps until the desired percentage of detectable bridging faults are examined.

Abstract: A novel RS latch for use in asynchronous designs has been provided. The RS latch is made scannable by the use of additional circuitry which provides a basis for a scan chain signal to propagate in and out the scannable RS latch. Such a scannable RS latch greatly facilitates the testing of the asynchronous design.

Abstract: A method for generating and simulating test patterns to detect faults (57, 63) in an integrated circuit. The method comprises identifying all nets (27) which can potentially be shorted together. Each potential fault (34, 36, 37, 38, 39) is categorized as either a feedback fault or a non-feedback fault. A test pattern is generated to detect the selected potential fault. The test pattern is simulated to determine which additional potential faults are detected by the test pattern. Potential faults which are detected by the test pattern are deleted from the fault list (12). The method is repeated until no potential faults remain on the fault list (12).

Abstract: A CMOS logic circuit uses a boost transistor responsive to a pulse signal to rapidly charge and/or discharge the output node during predetermined transitions of the input signal and provide a selectable slew rate for one edge of the output signal. A pulse generator circuit provides the pulse signal of predetermined width at a first transition of the input signal and disables the pulse signal and boost transistor before the following transition to avoid adversely effecting the opposite edge of the output signal. The width of the pulse signal and the size of the boost transistor determines the slew rate of the output signal for the edge under control. Many types of logic circuits such as inverters, NAND gates and NOR gates may utilize dual boost transistors and pulse generator circuits for separate control over both output edge rates without adversely affecting the opposite edge.

Abstract: A CMOS transmission gate circuit having a pass transistor and a feedback transistor is coupled across a logic gate. The pass transistor is responsive to a control signal for passing a logic signal. The feedback transistor aids the pass transistor in passing a first logic voltage level when the output signal of the logic gate is a second logic voltage level. Further, the speed performance of the CMOS transmission gate circuit is not degraded if the feedback transistor fails.

Abstract: When testing one circuit block of a device, it is desired to have isolation from the other circuit blocks of the device so as to prevent possible failure of the other circuit blocks. A block isolation buffer includes a circuit for providing predetermined voltage levels at the inputs of the circuit blocks which are not being tested thereby assuring that an undesired input does not appear at the inputs of the non-tested circuit blocks.