International Business Machines Corporation

Rafael Blanco

Sebastian Theodore Ventrone

Kenneth Joseph Goodnow

John Maxwell Cohn

Douglas Willard Stout

Brian William Curran

Michael Anthony Sorna

Marcel A Kossel

Jack Robert Smith

Francis A Kampf

Suzanne Granato

Douglas Thomas Massey

Multi-protocol driver slew rate calibration systems for calibrating slew rate control signal values are provided. Embodiments include generating, by a first phase rotator, a first clock signal; generating, by the second phase rotator, a second clock signal; initially setting, by a calibration controller, phase selector amounts such that the first clock signal is delayed relative to the second clock signal; determining whether the first clock signal is delayed relative to the second clock signal; if the first clock signal is delayed, changing the second phase selector amount; and if the first clock signal is not delayed, using the first clock signal and the second clock signal to calibrate values of control signals provided to control a slew rate of a calibration clock delay line such that the slew rate of the calibration clock delay line substantially matches a target slew rate.

Multi-protocol driver slew rate calibration system for calibration slew rate control signal values

The invention provides for selectively changing a line width for a memory, i.e., selecting one of a plurality of line widths for a memory. The selected line width is used in communicating with one or more processors. This provides increased flexibility and efficiency for communicating with the memory. In particular, a register can be set based on a desired line width, and subsequently used when locating data in the memory. The selected line width can be associated with each data block in the memory to allow multiple line widths to be used simultaneously. When implemented in a cache, multiple ways of the cache can be processed as a group to provide data during a single memory operation. The line width can be varied based on a task, a processor, and/or a performance evaluation.

Selectively changeable line width memory

A method and system for testing a circuit design. The method including generating a simulation model of the circuit design, the circuit design comprising one or more source latches, one or more destination latches and a logic function connected between the source latches and the destination latches; generating a modified simulation model of the simulation model by inserting random skew between an output of each source latch and an input of the logic function only in asynchronous data paths between the source latches and the destination latches of the simulation model; and running the modified simulation model.

Simulation testing of digital logic circuit designs

An integrated circuit has a power grid and a set of independently switchable voltage islands, together with a system and method for measuring the voltage and history of the voltage on the power grid to determine the correct time to allow a large capacitive load (such as a voltage island) to be switched on to or off the power grid.

Method of switching voltage islands in integrated circuits when a grid voltage at a reference location is within a specified range

A structure and associated method of processing data on a semi-conductor device comprising an input island, a processing island, and an output island formed on the semiconductor device. The input island is adapted to accept a specified amount of data and enable a means for providing a first specified voltage for powering the processing island after accepting the specified amount of data. The processing island is adapted to receive and process the specified amount of data from the input island upon powering the processing island by the first specified voltage. The output island is adapted to be powered by a second specified voltage. The processing island is further adapted to transmit the processed data to the output island upon said powering by the second specified voltage. The first specified voltage is adapted to be disabled thereby removing power from processing island upon completion of transmission of the processed data to the output island.

Power down processing islands

A circuit for fencing input signals to circuits in a voltage island when switching between a normal and a standby power supply is disclosed. A voltage detector detects the switch over in power source and generates a power switch signal. The power switch signal is synchronized to a standby clock and a normal clock. The synchronized standby clock signal is delayed by a counter to allow circuit stabilization. The normal and standby clock signals are logically combined and used to fence input signals to the circuits on the voltage islands.

Voltage island fencing

A programmable, timing signal generator propagates a digital wave along a delay chain comprised of series connected inverters that has sufficient stages that the edge of the wave will not propagate to the end during one system clock cycle time. The delay chain is sampled once each clock cycle, and the point to which the wave has progressed is encoded. Programmable, fine leading and fine trailing edge registers store, as a fraction of the clock cycle time, the desired locations of the timing signal leading and trailing edge relative to the clock edges.

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Essex Junction, VT, United States of America

Rafael Blanco