Abstract: A logical design method for a semiconductor integrated circuit includes the steps of: a) generating a circuit at a logical level so as to meet given functions and specifications; b) extracting a critical path, which will cause the longest delay, from the circuit generated in the step a); c) counting how many times a path leading from each input terminal to an output terminal in every logic cell of the circuit has operated; d) calculating a degradation rate associated with the path leading from each said input terminal to the output terminal in each said logic cell on the critical path by reference to the number of times of operation obtained in the step c); and e) exchanging a connection to one of the input terminals of each said logic cell, which terminal is associated with the critical path, with a connection to another one of the input terminals of the logic cell, which terminal is associated with another path corresponding to a lower degradation rate than that of the critical path, by reference to the deg

Abstract: A logical design method for a semiconductor integrated circuit includes the steps of: a) generating a circuit at a logical level so as to meet given functions and specifications; b) extracting a critical path, which will cause the longest delay, from the circuit generated in the step a); c) counting how many times a path leading from each input terminal to an output terminal in every logic cell of the circuit has operated; d) calculating a degradation rate associated with the path leading from each said input terminal to the output terminal in each said logic cell on the critical path by reference to the number of times of operation obtained in the step c); and e) exchanging a connection to one of the input terminals of each said logic cell, which terminal is associated with the critical path, with a connection to another one of the input terminals of the logic cell, which terminal is associated with another path corresponding to a lower degradation rate than that of the critical path, by reference to the deg

Abstract: A logical design method for a semiconductor integrated circuit includes the steps of: a) generating a circuit at a logical level so as to meet given functions and specifications; b) extracting a critical path, which will cause the longest delay, from the circuit generated in the step a); c) counting how many times a path leading from each input terminal to an output terminal in every logic cell of the circuit has operated; d) calculating a degradation rate associated with the path leading from each said input terminal to the output terminal in each said logic cell on the critical path by reference to the number of times of operation obtained in the step c); and e) exchanging a connection to one of the input terminals of each said logic cell, which terminal is associated with the critical path, with a connection to another one of the input terminals of the logic cell, which terminal is associated with another path corresponding to a lower degradation rate than that of the critical path, by reference to the deg

Abstract: The present invention makes it possible to obtain an aging deterioration margin amount including an allowance for aging deterioration in a simplified manner. Moreover, in order to allow an appropriate inspection taking aging deterioration into account, a delay deterioration rate predicting part 101 outputs signal path delay information before deterioration 302 and signal path delay deterioration rate information 303 for each signal path, based on LSI design information 301. A delay vs. delay deterioration rate analyzing part 102 outputs delay vs. delay deterioration rate relationship information 304 showing the correlation between the delay and the delay deterioration rate based on the information. A delay deterioration rate extracting part 103 extracts a delay deterioration rate of a predetermined signal path and outputs it as delay deterioration margin 305.

Abstract: An approach for simulating hot carrier effects in an integrated circuit (IC) at the circuit level includes generating a hot carrier library of delay data for each cell in the IC, using the hot carrier library data to generate a set of scaled timing data for the IC and using the scaled timing data with a IC performance simulator to simulate the IC operation. The scaled timing data is based upon the cell delay data and time-based switching activity of each cell in the IC.

Abstract: There is provided a hot-carrier-delay-degradation estimation method of estimating, based on the actual operation of an LSI, deterioration in reliability thereof due to the influence of hot carriers. At a delay calculation step, there are calculated, for the cells of an LSI serving as the object of timing verification, delays, input slew and output load capacitances based on circuit information and a delay library containing delay parameters. At a delay degradation library generation step, there is generated a delay degradation library containing delay parameters at the time when the LSI has operated for a predetermined period of time.

Abstract: A compiling method comprises the steps of analyzing the characters and phrases in the source code of a program, analyzing the syntax of the program, and analyzing the meaning of the program, a program division step of dividing the program into a plurality of processes, a data reference analysis step of analyzing the data reference relations among the individual processes obtained through the division of the program and extracting first data used only in one process of the program and second data the value of which need not be preserved in some processes of the program, a memory area allocation step of allocating the memory area for the above first data to another data in any process in which the above first data is not used and allocating the memory area for the above second data to another data in some processes in which the value of the above second data need not be preserved, and the step of generating and outputting the object code of the program.

Abstract: Signal propagation delay in an inverter chain having a first inverter cell and a second inverter cell connected by an intercell wire, is evaluated. In order to guarantee that a first inverter cell delay is always evaluated to be positive (A) a logic threshold voltage for an increase in input pin voltage of the first inverter cell is set to a voltage below a switching threshold voltage of the first inverter cell, and (B) a logic threshold voltage for a decrease in input pin voltage of the first inverter cell is set to a voltage above the switching threshold voltage of the first inverter cell. Similarly, logic threshold voltages for an increase and a decrease in input pin voltage of the second inverter cell are determined. Additionally, in order to guarantee that an intercell wire delay is always evaluated to be positive, logic threshold voltages for an output pin voltage of the first inverter cell are made to agree with the logic threshold voltages for the input pin voltage of the second inverter cell.