International Business Machines Corporation

Ivan Vo

Juan-Antonio Carballo

Kevin John Nowka

Jeffrey L Burns

Seung-moon Yoo

Gary Dale Carpenter

Fadi Hikmat Gebara

Seung-Moon Yoo

Jayakumaran Sivagnaname

David William Boerstler

Ying Liu

Jente Benedict Kuang

Hung Cai Ngo

Quan Nguyen

Embedded dynamic random access memory (eDRAM) sense amplifier circuitry in which a bit line connected to each of a first plurality of eDRAM cells is controlled by cell control lines tied to each of the cells. During a READ operation the eDRAM cell releases its charge indicating its digital state. The digital charge propagates through the eDRAM sense amplifier circuitry to a mid-rail amplifier inverter circuit which amplifies the charge and provides it to a latch circuit. The latch circuit, in turn, inverts the charge to correctly represent at its output the logical value stored in the eDRAM cell being read, and returns the charge through the eDRAM sense amplifier circuitry to replenish the eDRAM cell.

High performance eDRAM sense amplifier

A digital transmission circuit and interface provide selectable power consumption via multiple weighted driver slices, improving the flexibility of an interface while reducing transmitter power consumption, area and complexity when possible. A cascaded series of driver stages is provided by a set of parallel slices and a control logic that activates one or more of the slices, which combine to produce a cascaded active driver circuit. The power consumption/drive level selectability of the slice combination provides a driver that can be fine-tuned to particular applications to provide the required performance at a minimum power consumption level.

Digital transmission circuit and interface providing selectable power consumption via multiple weighted driver slices

A digital transmission circuit and method providing selectable power consumption via multiple weighted driver slices improves the flexibility of an interface while reducing power consumption when possible. A cascaded series of driver stages is provided by a set of parallel slices and a control logic that activates one or more of the slices, which combine to produce a cascaded active driver circuit. The power consumption/drive level selectability of the slice combination provides a driver that can be fine-tuned to particular applications to provide the required performance at a minimum power consumption level.

Digital transmission circuit and method providing selectable power consumption via multiple weighted driver slices

A digital transmission circuit and method providing selectable power consumption via single-ended or differential operation improves the flexibility of an interface while reducing power consumption when possible. A differential path is provided through the transmitter output driver stages and portions are selectively disabled when the transmission circuit is in a lower-power operating mode. A single-ended to differential converter circuit can be used to construct a differential signal for output to the final driver stage. The selection of power mode can be made via feedback from a channel quality measurement unit or may be hardwired or selected under programmatic control. The longer delay or skew of the lower-power single-ended mode is compensated for by the relaxed requirements of the channel when conditions permit the use of the lower-power single-ended mode.

Digital transmission circuit and method providing selectable power consumption via single-ended or differential operation

A method of reducing power consumption while maintaining performance characteristics and avoiding costly over-design of a high-speed communication link embedded in an SOC is provided. The method includes synthesizing the communication link at a reduced voltage to determine and isolate circuitry that is supply-voltage-critical from circuitry that is non-supply-voltage-critical. The supply-voltage-critical circuitry contains components that may not operate at the reduced voltage without degrading the performance characteristics of the communication link. A non-reduced voltage is used to drive the supply-voltage-critical circuitry while the reduced voltage is used to drive the non-supply-voltage-critical circuitry. The reduced voltage is generated using a voltage regulator embedded in the communication link.

Method of transparently reducing power consumption of a high-speed communication link

An active cancellation matrix for process parameter measurements provides feedback paths for each test location wherein each feedback path is used to sense the applied voltage and the sensed voltage is used to adjust the source voltage for any variations along the input path. The devices under test are arranged in a row and column array, and the feedback and voltage input paths are formed along respective rails which extend generally parallel to a row of devices under test. Selectors are used to selectively route the outputs of the test nodes to a measurement unit such as a current sensor. The input voltages can be varied to establish current-voltage (I-V) curves for the devices under various conditions. In the example where the devices under test are transistors, each source input includes three voltage inputs (rails) for a drain voltage, a source voltage, and a gate voltage.

Active cancellation matrix for process parameter measurements

A digital transmission circuit and method providing selectable power consumption via multiple weighted driver slices improves the flexibility of an interface while reducing transmitter power consumption, area and complexity when possible. A cascaded series of driver stages is provided by a set of parallel slices and a control logic that activates one or more of the slices, which combine to produce a cascaded active driver circuit. The power consumption/drive level selectability of the slice combination provides a driver that can be fine-tuned to particular applications to provide the required performance at a minimum power consumption level.

Digital transmission circuit and method providing selectable power consumption via multiple weighted drive slices

A method and apparatus for measuring communications link quality provides accurate on-chip estimation of the difficulty of achieving a particular bit error rate (BER) for a communications link. A low cost/complexity accumulator circuit connected to internal signals from a clock/data recovery (CDR) circuit provides a measure of high frequency and low frequency jitter in a received signal. The low frequency jitter measurement is used to correct the high frequency jitter measurement which may otherwise contain error. The corrected output may be used to adjust operational characteristics of the link or otherwise evaluate the link for operating margin. The correction may be performed by subtracting a portion of the low frequency jitter measurement from the measured high frequency jitter, or the value of the low frequency jitter measurement may be used to select between two or more correction factors that are then applied to the high frequency jitter measurement.

Method and apparatus for measuring communications link quality

According to an apparatus form of the invention, integrated circuitry on a single chip includes a bit-programmable voltage regulator supplying voltage to first circuitry on the chip. The integrated circuitry also includes second circuitry operable for characterizing performance of the first circuitry. Control circuitry on the chip is operable, responsive to the characterizing performed by the second circuitry, to output at least one digital control bit for controlling the regulator output voltage supplying the first circuitry. In another aspect, the integrated circuitry is operable to receive an externally generated, time-based reference signal, and the second circuitry includes an on-chip oscillator for generating a performance characterizing signal. The performance characterizing signal varies in frequency in correspondence with the performance of the first circuitry. The control circuitry receives the reference signal and the performance characterizing signal and responsively generates the at least one control bit.

Method and apparatus for control of voltage regulation

According to an apparatus form of the invention, oscillator circuitry for operating a number of inverters in a loop (also known as a &ldquo;ring&rdquo;) includes a number of inverters. The inverters include a series of M inverters and a series of N inverters. The M inverters have signal propagation delay of m and the N inverters have signal propagation delay of n. The circuitry also includes means for selecting whether to exclude the N inverters from operating in the loop operable for receiving a select signal on a data input. The selecting means times assertion of the select signal on an output to select the number of inverters. In order to glitchlessly change the number of inverters operating in the loop, the selecting means has a certain delay greater than delay n.

Glitchless wide-range oscillator, and method therefor

In a first form, a voltage controlled oscillator includes delay cells connected in a ring, and control elements connected to selectively bypass respective sets of the delay cells. The delay cells are operable to receive respective differential inputs and to generate inverted outputs. The control elements are operable to receive respective differential inputs and to generate non-inverted outputs with variable delays. The control element delays are variable responsive to respective differential control voltages.

Differential voltage controlled oscillator, and method therefor

First current is conducted through a first path to adjust a voltage at a node toward a predetermined level in response to the voltage being within a first subrange of voltages. Second current is conducted through a second path to adjust the voltage at the node toward the predetermined level in response to the voltage being within a second subrange of voltages.

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Austin, TX, United States of America

Ivan Vo