International Business Machines Corporation

Ulrich Krauch

Wilhelm Ernst Haller

Kurt Lind

Markus Kaltenbach

Juergen Pille

Christian Zoellin

Nicolas Maeding

Friedrich Schroeder

Alexander Albert Woerner

Thomas Ludwig

Holger Wetter

Manuel Beck

Eric M Schwarz

Dieter F Wendel

Tobias Werner

Michael B Kugel

Alexander Fritsch

Antje Mueller

Stefan Zimmermann

Guenter Mayer

Juergen Haas

A circuit is provided for addition of multiple binary numbers. The circuit includes a 4-to-2-compressor configured for calculating a compressed representation from four binary numbers received via operand inputs of the 4-to-2-compressor. The 4-to-2-compressor includes a first sub-circuit and a second sub-circuit. Each of the first sub-circuit and the second sub-circuit is configured for transmitting a bitwise inverted representation, of a compressed representation, from three binary numbers.

Circuit for addition of multiple binary numbers

An integrated circuit chip includes at least two integrated circuits, at least three scan chains, and a multiplexor circuitry. Each integrated circuit includes an integrated circuit input port and an integrated circuit output port. The scan chains and the integrated circuits are coupled by default with a series chain having integrated circuits and scan chains alternating each other. The series chain starts with an initial scan chain and ends with the end scan chain. Each scan chain except the initial one includes a first scan chain input port coupled by default with the integrated circuit output port of the respective adjacent integrated circuit. Each scan chain except the end one includes a first scan chain output port coupled by default with the integrated circuit input port of the respective adjacent integrated circuit.

Integrated circuit chip and a method for testing the same

Automated analyzing of an endpoint report for a design of an electronic circuit is provided, which includes: identifying, by a processing device, that one or more test points of a selected path of the endpoint report are associated with one or more inverter devices of an inverter chain of the design of the electronic circuit; establishing, by the processing device, a chain criticality value for the inverter chain; and determining, by the processing device, whether to identify the inverter chain as a dispensable inverter chain, the determining using, at least in part, the chain criticality value for the inverter chain. The establishing may include updating the chain criticality value for each inverter device of the inverter chain, where the chain criticality value is a summed value obtained from criticality values for the one or more inverter devices of the inverter chain.

Detecting dispensable inverter chains in a circuit design

The invention relates to a current sense amplifier () comprising a reference current input terminal (), a sense control line input terminal (), a sense current input terminal (), a first output terminal (), and a second output terminal (). The amplifier further comprises a first NAND gate () comprising an output terminal being connected to the first output terminal (), a second NAND gate () comprising an output terminal being connected to the second output terminal (), a first (T, T) and a second (T, T) cross coupled inverters, the first inverter comprising a first n-FET (T) and the second inverter comprising a second n-FET (T), a transmission gate () comprising a first and a second transmission terminal and a transmission control terminal, the transmission control terminal being connected to the sense control line input terminal (), an AND gate () having a first input terminal connected to the first output terminal () and a second input terminal connected to the second output terminal (), a third n-FET (T) having a gate connected to an output terminal of the AND gate (), a drain connected to the sense current input terminal, a source connected to ground, wherein a source of the first n-FET is connected to the sense current input terminal and a source of the second n-FET is connected to the reference current input terminal, a first input terminal of the first NAND gate and a first input terminal of the second NAND gate are connected to the sense control line input terminal, the first transmission terminal and a second input terminal of the first NAND gate are connected to an output terminal of the second inverter and the second transmission terminal and a second input terminal of the second NAND gate are connected to an output terminal of the first inverter.

Current-mode sense amplifier

An improved method for fixing an early mode slack in a hierarchically designed hardware device with at least one source macro, an integration unit and at least one sink macro comprises: Loading hardware design timing data to determine pins where an early mode slack fix can be applied to fix an early mode slack; for each such pin determining a location across the design hierarchy for the early mode slack fix by calculating a weight value for each of a selection of fix locations of the early mode slack based on absolute values of arrival times of data signals, ratio and difference between arrival times of late mode data signals and early mode data signals; and assigning the early mode slack fix to the determined location based on said weight value.

Method and system to fix early mode slacks in a circuit design

A method to generate a magnitude result of a mathematic operation of two decimal operands within one cycle in a decimal arithmetic logic unit structure, wherein the decimal operands are in hexadecimal sign magnitude format.

Method and decimal arithmetic logic unit structure to generate a magnitude result of a mathematic

A computer-readable storage storing instructions for a processor. Execution of the instructions causes loading unit timing data descriptive of an upper hierarchy. Execution of the instructions cause the loading of a unit timing path, and the loading of macro timing data into the memory. Execution of the instructions further cause the replacement of at least a portion of the unit timing report with the macro timing data, and computation of arrival times, slacks, and slews. Execution of the instructions also cause computation of path statistics in accordance with the arrival times, slacks and slews, and generation of a end point report for the unit timing path, including path statistics.

Generation of an end point report for a timing simulation of an integrated circuit

According to the present invention an automated method is provided for routing and designing an LSI (Large Scale Integrated Circuit). First, at least one generic of an instance of a book to be connected is located on the chip, wherein a generic of an instance is an area defined according to the measurements of said instance. Then, an initial route to said instance is generated by optimizing the route to the corresponding generic according to given design rules. Thereby, an optimized pin location is determined for said instance. Then, on the basis of said optimized pin location a layout for said instance is generated in place of the corresponding generic. Finally, the actually generated pin is connected with the corresponding end of the initial route.

Automatic method for routing and designing an LSI

Storage devices are presented which have some facility of error indication and error correction. The basic idea of the present invention is to double only the storing part inside the storing cell and share the environmental logic. Especially in case of multi-port cells this reduces the area penalty significantly because the read/write control within the cell is shared and only placed once. Writing the cell always writes both latches so that they hold the same data. A soft error can flip only one of the two latches. Then, a 'XOR' block detects that the data is no longer identical. While the data is read out the check bit indicates that the data is corrupted. The approach of doubling only the storing elements can be extended to implement a triple storing element ( ) in the same cell. Then, with the help of a small and simple error correction logic ( ) in the cell from a 'majority vote' can be seen which bit value is wrong in case of a soft error affecting one bit in the cell. Thus, no post-processing is necessary after reading the bit from the cell, as it is true per se. (FIG. ).

Storage cell with integrated soft error detection and correction

A combined adder and logic unit having a reduced operation delay of arithmetic and logic operations, and providing an improved fan in and reduced wiring delays and capacity if implemented in the arithmetic and logic section of a microprocessor chip. The unit comprises a carry network (30) connected to operand inputs for generating carry-out signals of the byte positions (By0-By7) and further comprises a pre-sum logic (32) having a bit function generator (42) and a sum generator (45, 46, 48). Said bit function generator derives from the operands Ai and Bi bit functions Gi, Pi which are provided as logic function output and as input to said sum generator for producing preliminary arithmetic functions (SUM0, SUM1) to anticipate carry-in signals of one or zero. A result selector (70) is controlled by a byte position carry-out signal (Cy55) from the carry network means and by operation control signals to select from the output of said pre-sum logic one of the arithmetic functions (SUM0, SUM1) or one of the logic functions as result of the unit operation.

Combined adder and logic unit

A combined binary/decimal adder unit reduces the operation delay ine processing binary coded decimal operands and permit an increased cycle rate of a processor unit in which the combined binary/decimal adder unit is utilized. Pre-sums are generated for each decimal digit position in parallel to the generation and distribution of the carries over the total of decimal digit positions of the adder unit. The pre-sums anticipate the carry-in of the decimal positions and the need to perform six corrections after the carry-out signal of the highest decimal digit position has been generated. The carry-out signal of each decimal digit position is used in combination with operation control signals to select the correct pre-sum of the digit position.

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Dettenhausen, Germany

Ulrich Krauch