摘要:
An adder circuit for adding two binary or two decimal operands A and B in which the carries are calculated directly from the input operands A and B without including the plus 6 or minus 6 operations into the carry calculation. For all timing critical functions the reduced input data set, i.e., valid decimal data can be used and the non-existing decimal numbers (10 to 15) need not be excluded by separate check logic any more. This reduces the complexity of the logic functions.
摘要:
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.
摘要:
A system for creating layout and wiring diagrams for an integrated circuit (IC) includes a placement engine configured to receive a hierarchical schematic and to create a placed layout. The system also includes a flat layout engine configured to receive the hierarchical schematic and to create a flat layout and a back annotation engine coupled to the placement engine and the flat layout engine, the back annotation engine configured to receive the hierarchical placed layout and the flat unplaced layout and to create a flat placed layout there from.
摘要:
A system for creating layout and wiring diagrams for an integrated circuit (IC) includes a placement engine configured to receive a hierarchical schematic and to create a placed layout. The system also includes a flat layout engine configured to receive the hierarchical schematic and to create a flat layout and a back annotation engine coupled to the placement engine and the flat layout engine, the back annotation engine configured to receive the hierarchical placed layout and the flat unplaced layout and to create a flat placed layout there from.
摘要:
A binary and decimal adder unit uses a pre-sum logic for generating pre-sums of the operands A, B under the presumption of one and zero carry inputs into the decimal digit position, and also uses a digits carry network for generating binary carries within the decimal digit positions and a high order carry out signal of said plurality of decimal digits. Each decimal digit position of said adder unit provides a six correction and a pre-sum selection. The pre-sum logic comprises a carry prediction logic for generating decimal digit position carry out signals on the presumption of a zero carry input and of a one carry input into the decimal digit. In response to gating signals derived from the carry out signals of the carry prediction logic and operation control signals a pre-selection is performed for selecting a qualified pre-sum generated on the presumption of a zero carry input into the decimal digit, and for selecting a qualified pre-sum generated on the presumption of a one carry input into the decimal digit. The pre-selection of the qualified pre-sums is performed for all decimal digit positions in parallel to the generation and distribution of the carries in the digits carry network over the total of decimal digit positions. The pre-sum selection logic further comprises a two way selector which is responsive to a digit carry-in signal from the digits carry network for selecting one the qualified pre-sums as the correct sum of the digit position. According to one embodiment of the invention, the pre-sum logic generates six corrected pre-sums which are included in the pre-selection of qualified pre-sums.
摘要:
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.
摘要:
A system for performing decimal floating point addition. The system includes input registers for inputting a first and second operand for an addition operation. The system also includes a plurality of adder blocks, each calculating a sum of one or more corresponding digits from the first operand and the second operand. Output from each of the adder blocks includes the sum of the corresponding digits and a carry out indicator for the corresponding digits. The calculating is performed during a first clock cycle. The system also includes an intermediate result register for storing the sums of the corresponding digits output from each of the plurality of adder blocks, the storing during the first clock cycle. The system further includes a carry chain for storing the carry out indicator output from each of the plurality of adder blocks, the storing occurring during the first clock cycle. The system further includes an incrementer for adding one to each of the sums stored in the intermediate result register, the incrementing occurring during a second clock cycle. In addition, a mechanism is provided for selecting between each of the sums and the sums incremented by one. The input to the mechanism includes the carry chain. The output includes the final sum of the first operand and the second operand. The selecting occurs during the second clock cycle.
摘要:
A computerized method, data processing system and computer program product reduce noise for a buffered design of an electronic circuit which was already placed and routed. For all areas between a power stripe and a ground stripe (half bay) in the design, the shapes are divided in different criticality levels. The shapes are rearranged based on their criticality level such that shapes with higher criticality level are placed closer to the stripes than those with lower criticality level.
摘要:
One or more processing units are connected with a clock component (comprising a clock) over a bi-directional serial link, and data frames are transmitted between the clock component and the processing units. The clock component may contain a serial link combination circuit for combining multiple processing unit serial links, operating in parallel, into a single serial link connected to the clock. Both of the clock component and the processing units contain an error detection and correction mechanism which examine and modify data within the data frames to perform error detection and correction. The clock component optionally contains an external interface for connection to a command-issuing Service Processor.
摘要:
A method, circuit apparatus, and a design structure on which the circuit resides, is provided to perform a subtraction of two operands in a binary arithmetic unit by subdividing two operands into groups of equal numbers of bits, generating, by appropriate arithmetic operations, pairs of intermediate results for the particular groups of bits of the two operands comprising the same bit positions, respectively. A first intermediate result of each pair of intermediate results is generated under the assumption of a carry-in of ‘0’ and a second intermediate result of each pair of intermediate results is generated under the assumption of a carry-in of ‘1’. The correct intermediate result of each particular pair of intermediate results from each group of bits is selected, and the result of the subtraction of the two operands is generated by an appropriate merging of the selected correct intermediate results.