Abstract: An adaptive voltage scaling system includes first and second devices. Each of the first and second devices includes at least one master serial interface port and at least one slave serial interface port. The first device is operatively coupled to a voltage regulator, and the slave serial interface port associated with the second device is operatively coupled to the master serial interface port associated with the first device. The first device controls the voltage regulator based on information obtained from the first and second devices using the master serial interface port associated with the first device and the slave serial interface port associated with the second device. The first and second devices receive voltage from the voltage regulator. A corresponding method and computer-readable medium are also disclosed.

Abstract: An integrated circuit having a monitor circuit for monitoring timing in a critical path having a target timing margin is disclosed. The monitor circuit has two shift registers, one of which includes a delay element that applies a delay value to a received signal. The inputs to the two shift registers form a signal input node capable of receiving an input signal. The monitor circuit also has a logic gate having an output and at least two inputs, each input connected to a corresponding one of the outputs of the two shift registers. The output of the logic gate indicates whether the target timing margin is satisfied or not satisfied.

Abstract: An integrated circuit implements a transistor mismatch sensor comprising first and second inverter chains coupled to a register. The register comprises a plurality of flip-flops having clock inputs driven by an output of the first inverter chain and data inputs driven by an output of the second inverter chain. Data outputs of the flip-flops of the register are indicative of an amount of mismatch between transistors of different conductivity types in the first and second inverter chains. For example, the register may comprise a thermometer encoded register providing a digital output signal having a first value indicative of an approximate match in speed, drive strength or other characteristics between the transistors of the first and second conductivity types, with values above and below the first value being indicative of respective first and second different types of relative mismatch in speed, drive strength or other characteristics.

Abstract: An integrated circuit implements a transistor aging effects sensor comprising first and second delay lines, each comprising a plurality of delay elements, and a register. The register comprises a plurality of flip-flops having data inputs driven by respective outputs of respective ones of the delay elements of the first delay line and clock inputs driven by one or more clock signals provided by at least one of the delay elements of the second delay line. Data outputs of the flip-flops of the register are indicative of one or more aging effects in transistors of the first and second delay lines. For example, the register may comprise a thermometer encoded register providing digital output signals used to determine aging effects in the transistors of the first and second delay lines. Embodiments can be implemented using differential delay lines or delay lines comprising respective inverter chains.

Abstract: A delay circuit having reduced duty cycle distortion is provided. The delay circuit includes a plurality of delay elements connected together in a series configuration. Each of the delay elements has a prescribed delay associated therewith. The delay circuit further includes a controller connected to respective outputs of the delay elements. The controller is configured such that signal paths between the respective outputs of the delay elements and an output of the controller have delays that are substantially the same relative to one another. Each of the signal paths has a tri-statable switching element associated therewith.

Abstract: An adaptive voltage scaling system includes first and second devices. Each of the first and second devices includes at least one master serial interface port and at least one slave serial interface port. The first device is operatively coupled to a voltage regulator, and the slave serial interface port associated with the second device is operatively coupled to the master serial interface port associated with the first device. The first device controls the voltage regulator based on information obtained from the first and second devices using the master serial interface port associated with the first device and the slave serial interface port associated with the second device. The first and second devices receive voltage from the voltage regulator. A corresponding method and computer-readable medium are also disclosed.

Abstract: An integrated circuit having a monitor circuit for monitoring timing in a critical path having a target timing margin is disclosed. The monitor circuit has two shift registers, one of which includes a delay element that applies a delay value to a received signal. The inputs to the two shift registers form a signal input node capable of receiving an input signal. The monitor circuit also has a logic gate having an output and at least two inputs, each input connected to a corresponding one of the outputs of the two shift registers. The output of the logic gate indicates whether the target timing margin is satisfied or not satisfied.

Abstract: In one embodiment, the invention is a method for modeling electrical behavior of a packaged module having multiple integrated circuits (ICs), such as a multi-chip module (MCM). The method includes: (a) identifying one or more pin groups in the module, wherein a pin group comprises two or more buffers connected together and to a package-external pin, and (b) generating one or more corresponding unified behavioral models for the one or more pin groups based on the characteristics of the buffers of the one or more pin groups. The behavioral models are part of an integrated behavioral model file in accordance with the I/O buffer information specification (IBIS) standard.

Abstract: Techniques for enhancing the performance of an IC are provided. A method of enhancing IC performance includes the steps of: associating at least one performance result of at least one performance monitor, formed on the IC, with deterministic combinations of IC performance and a processing parameter, a supply voltage, and/or a temperature of the IC; determining an IC processing characterization of the IC as a function of the performance result for at least one prescribed supply voltage and temperature of the IC, the IC processing characterization being indicative of a type of processing received by the IC during fabrication of the IC; and controlling a voltage supplied to at least a portion of the IC, the voltage being controlled as a function of the IC processing characterization and/or the temperature of the IC so as to satisfy at least one prescribed performance parameter of the IC.

Abstract: An integrated circuit having a monitor circuit for monitoring timing in a critical path having a target timing margin is disclosed. The monitor circuit has two shift registers, one of which includes a delay element that applies a delay value to a received signal. The inputs to the two shift registers form a signal input node capable of receiving an input signal. The monitor circuit also has a logic gate having an output and at least two inputs, each input connected to a corresponding one of the outputs of the two shift registers. The output of the logic gate indicates whether the target timing margin is satisfied or not satisfied.

Abstract: Generally, methods and apparatus are provided for deriving an integrated circuit (IC) clock signal with a frequency that is offset from the IC system clock. An offset clock having a frequency that is offset from a system clock is generated by configuring a ring oscillator in a first mode to generate the system clock having a desired frequency; and adjusting the configuration of the ring oscillator in a second mode to generate the offset clock having the frequency that is offset from the system clock. The configuration of the ring oscillator is adjusted in the second mode by adjusting (i) a power supply value applied to the ring oscillator in the second mode relative to a power supply value applied in the first mode; or (ii) a number of delay line elements that are active in the ring oscillator loop.

Abstract: A method of operating an embedded memory having (i) a local memory, (ii) a system memory, and (iii) a multi-level cache memory coupled between a processor and the system memory. According to one embodiment of the method, a two-level cache memory is configured to function as a single-level cache memory by excluding the level-two (L2) cache from the cache-transfer path between the processor and the system memory. The excluded L2-cache is then mapped as an independently addressable memory unit within the embedded memory that functions as an extension of the local memory, a separate additional local memory, or an extension of the system memory.

Abstract: Techniques for enhancing the performance of an IC are provided. A method of enhancing IC performance includes the steps of: associating at least one performance result of at least one performance monitor, formed on the IC, with deterministic combinations of IC performance and a processing parameter, a supply voltage, and/or a temperature of the IC; determining an IC processing characterization of the IC as a function of the performance result for at least one prescribed supply voltage and temperature of the IC, the IC processing characterization being indicative of a type of processing received by the IC during fabrication of the IC; and controlling a voltage supplied to at least a portion of the IC, the voltage being controlled as a function of the IC processing characterization and/or the temperature of the IC so as to satisfy at least one prescribed performance parameter of the IC.

Abstract: Generally, methods and apparatus are provided for deriving an integrated circuit (IC) clock signal with a frequency that is offset from the IC system clock. An offset clock having a frequency that is offset from a system clock is generated by configuring a ring oscillator in a first mode to generate the system clock having a desired frequency; and adjusting the configuration of the ring oscillator in a second mode to generate the offset clock having the frequency that is offset from the system clock. The configuration of the ring oscillator is adjusted in the second mode by adjusting (i) a power supply value applied to the ring oscillator in the second mode relative to a power supply value applied in the first mode; or (ii) a number of delay line elements that are active in the ring oscillator loop.

Abstract: A PCB having fewer off-chip memories than chips, a MCM, and a method of accessing an off-chip shared memory space. In one embodiment, the method includes: (1) generating a memory request at a first chip of the printed circuit board, (2) transforming the memory request to a shared memory request and (3) directing the shared memory request to an off-chip shared memory space indirectly coupled to the first chip via a second chip of the printed circuit board.

Abstract: A delay circuit having reduced duty cycle distortion is provided. The delay circuit includes a plurality of delay elements connected together in a series configuration. Each of the delay elements has a prescribed delay associated therewith. The delay circuit further includes a controller connected to respective outputs of the delay elements. The controller is configured such that signal paths between the respective outputs of the delay elements and an output of the controller have delays that are substantially the same relative to one another. Each of the signal paths has a tri-statable switching element associated therewith.

Abstract: Apparatus for correcting clock skew in a circuit including at least one sequential circuit element and a clock generator operatively coupled to the sequential circuit element includes at least one programmable delay element connected in series with a data input and/or a clock input of the sequential circuit element. The programmable delay element has a delay associated therewith which is selectively controllable as a function of a control signal. The apparatus further includes at least one processor connected in a feedback configuration with the sequential circuit element. The processor is operative to receive a clock signal generated by the clock generator and an output signal of the sequential circuit element and to generate the control signal as a function of the clock signal and the output signal. The processor is further operative to control a timing of a data signal supplied to the data input of the sequential circuit element.

Abstract: A system for a backplane that employs i) an adjustment of positive-to-negative (P-N) driver skew of a transmit signal of a relatively high-speed differential driver to reduce far-end crosstalk, ii) a high-speed differential subtraction circuit combining a gain-adjusted replica of at least one transmit signal with a received signal to reduce near-end crosstalk, and iii) a phase-locked loop (PLL) synchronization circuit to align timing events between a set of near-end and far-end high-speed interfaces.

Abstract: In one embodiment, the invention is a method for modeling electrical behavior of a packaged module having multiple integrated circuits (ICs), such as a multi-chip module (MCM). The method includes: (a) identifying one or more pin groups in the module, wherein a pin group comprises two or more buffers connected together and to a package-external pin, and (b) generating one or more corresponding unified behavioral models for the one or more pin groups based on the characteristics of the buffers of the one or more pin groups. The behavioral models are part of an integrated behavioral model file in accordance with the I/O buffer information specification (IBIS) standard.

Abstract: Methods and apparatus are provided for adaptive determination of timing signals, such as on a high speed parallel bus. The invention adaptively determines a timing signal having a first edge with respect to an internal clock, wherein the timing signal includes a period in which the timing signal is undriven, followed by a period immediately before a first transition in which the timing signal is in a predefined state. The timing signal is evaluated using one or more comparators; and an output of the one or more comparators are latched based on a clock signal. The clock signal is adjusted until the one or more comparators indicate the timing signal is in the known and valid state. The clock signal is further adjusted until the one or more comparators indicate the first transition has been reached. Thereafter, a gating control signal is established based on a timing of the first transition.