Abstract: A system is to receive a word on which to perform error correction; obtain segments, from the word, each segment including a respective subset of samples; update, on a per segment basis, the word based on extrinsic information associated with a previous word; identify sets of least reliable positions (LRPs) associated with the segments; create a subset of LRPs based on a subset of samples within the sets of LRPs; generate candidate words based on the subset of LRPs; identify errors within the word or the candidate words; update, using the extrinsic information, a segment of the word that includes an error; determine distances between the candidate words and the updated word that includes the updated segment; identify best words associated with shortest distances; and perform error correction, on a next word, using other extrinsic information that is based on the best words.

Abstract: A system is configured to receive a word that includes a group of samples; randomly select a subset of the samples; identify first samples, from the subset, with a lowest level of reliability; select another subset of the samples; identify second samples, from the other subset, with a lowest level of reliability; and create a merged subset based on selected first samples and selected second samples. The system is also configured to select a further subset of the samples; identify third samples, from the further subset, with a lowest level of reliability; identify fourth samples, from the merged subset, associated with a lowest level of reliability; create another merged subset based on a greater probability that fourth samples than third samples are included in the other merged subset; and generate another word based a sample from the other merged subset; and process the word using the other word.

Abstract: A system, method, and apparatus is disclosed for interpolation of an output of an analog to digital converter (ADC) to enable operation of the ADC at a sampling rate that is independent of the sampling rate for a DSP core so as to efficiently enable operation at higher date rates. According to one of the embodiments, an interpolation circuit is coupled between the ADC and DSP core and receives a first plurality of samples of data at the first data rate from the ADC and supplies a plurality of samples of second data at a second data rate to the DSP core; the second data rate being less than the first data rate. According to one of the embodiments, the interpolation circuit includes a memory and a FIR filter circuit having filter tap coefficient values selected to provide attenuation at high frequencies to reduce aliasing noise.

Abstract: A system is configured to receive a block of symbols, associated with a phase-modulated signal that includes data symbols that correspond to a payload associated with the signal, and control symbols; process the control symbols to identify an amount of phase noise associated with the control symbols; reset a phase, associated with each of the data symbols, based on the amount of phase noise and a reference phase; interleave the respective data samples, of each of the data symbols with other data samples, where the interleaved respective data samples cause errors, associated with the respective data samples, to be spread out among the other data samples and reduces an error rate relative to a prior data rate that existed before the interleaving; and perform forward error correction on the interleaved respective data samples.

Abstract: In one implementation, a device may include a voltage regulator circuit, a data processing circuit, and an error correction circuit, where the error correction circuit may correct errors in data processed by the data processing circuit to obtain error-corrected data and output an error-corrected version of the processed data. Additionally, an error monitor circuit may output an error signal indicative of a level of the errors in the processed data. A control circuit may receive the error signal and control the voltage regulator circuit to adjust, based on the error signal, the supply voltage to the data processing circuit. In some implementations, the control circuit may also base its decision to control the voltage regulator circuit based on available timing margins in the data processing circuit.

Abstract: Filter implementation using Hermitian conjugates and time division multiplexing (TDM) is disclosed to more efficiently compensate for chromatic dispersion of optical signals transmitted over a fiber optic medium. Embodiments for an input, filter, and output sections of a Digital Signal Processor (DSP) are described. The disclosed methods, and corresponding apparatus and systems enables a substantial reduction in the complexity of the hardware needed to implement CD compensation in the DSP. According to another embodiment, Inverse-Fourier transform circuits receive TDM data from the filter section and assemble the TDM data format back to a non-TDM format.

Abstract: A system, method, and apparatus is disclosed for interpolation of an output of an analog to digital converter (ADC) to enable operation of the ADC at a sampling rate that is independent of the sampling rate for a DSP core so as to efficiently enable operation at higher date rates. According to one of the embodiments, an interpolation circuit is coupled between the ADC and DSP core and receives a first plurality of samples of data at the first data rate from the ADC and supplies a plurality of samples of second data at a second data rate to the DSP core; the second data rate being less than the first data rate. According to one of the embodiments, the interpolation circuit includes a memory and a FIR filter circuit having filter tap coefficient values selected to provide attenuation at high frequencies to reduce aliasing noise.

Abstract: Filter implementation using Hermitian conjugates and time division multiplexing (TDM) is disclosed to more efficiently compensate for chromatic dispersion of optical signals transmitted over a fiber optic medium. Embodiments for an input, filter, and output sections of a Digital Signal Processor (DSP) are described. The disclosed methods, and corresponding apparatus and systems enables a substantial reduction in the complexity of the hardware needed to implement CD compensation in the DSP. According to another embodiment, Inverse-Fourier transform circuits receive TDM data from the filter section and assemble the TDM data format back to a non-TDM format.

Abstract: A technique for testing a static random access memory comprising at least the first port and a second port is disclosed. In one embodiment, the technique may be realized by testing the memory with values through the first port while applying one of a shadow write and a shadow read from the second port and testing the memory through the second port while applying one of the shadow write and the shadow read from the first port. The shadow write may be designed to write specified values into cells of the memory not being tested where the specified values are opposite to values used in testing the memory. The shadow read may be designed to read values from memory that are opposite to the values used in testing the memory.

Abstract: An interconnect delay test uses the IEEE 1149.1 standard test access port (TAP) controller. No modification of standard boundary cells is required. Since the standard boundary scan cells are used, circuit board and/or backplane interconnect delay tests do not affect ASIC (application specific integrated circuit) designs. It allows board and system designers to add new interconnect AC tests for any signals at any time without modification of ASICs. Since the method has no impact on the operations of the standard TAP controller, it is possible to use available test softwares for interconnect DC tests to perform the proposed delay test. The method can also be integrated as part of in-system interconnect tests.

Abstract: A method for and apparatus of testing a multi-port RAM (random access memory) detect single port faults and inter port shorts in multi-port random access memories. The algorithm performs a conventional single-port test such as MARCH or SMARCH on one port of the memory and performs an inter-port test on all other ports. The algorithm does not impose any extra test time and requires the addition of only a few gates to a conventional single-port BIST controller, independently of the size of the memory. An address to select ports of the multi-port RAM includes a row address signal of a plurality of bits. A specific bit of the row address signal is changed.

Abstract: An analytical fault diagnostic methodology for use in complex VLSI chips. The method assumes a scan design environment and is capable of locating errors to the scan flops that capture the errors during test, independently of the number of errors that the circuit-under-test produces. The methodology is also capable of identifying the test vector or vectors under which the errors are generated. The apparatus which is designed to implement the method is also described. As the apparatus requires little hardware, the method is practical for chip level applications.

Abstract: A method of testing a digital integrated circuit for faults. A plurality of n check points l.sub.1, l.sub.2, . . . , l.sub.n are established to define a test sequence. A set of m references r.sub.1, r.sub.2, . . . , r.sub.m are predefined, corresponding to the signatures which the circuit would produce at the corresponding check points in the absence of any faults. A test sequence is applied to the circuit and an output signature s.sub.i is derived from the circuit at the corresponding check point l.sub.i. The output signature is compared with each member of the set of references. The circuit is declared "good" if the signature matches at least one member of the set of references, or "bad" if a signature matches no members of the set of references. Testing proceeds in similar fashion at the next check point, until the circuit has been tested at all check points.