30results about How to "Short simulation time" patented technology

Provided are an evaluation method and device of a test pattern which enable an appropriate evaluation in a reliability test with a simulation time reduced and high accuracy. It is assumed that each possible internal state of a cell determined at least by a logic value or a voltage value of an input terminal is a cell state, and each possible state of a transistor determined by a voltage between terminals of the transistor is a transistor state. The method comprises steps of: verifying operation of a semiconductor integrated circuit at a gate level or higher; acquiring an appearance cell state continuously appearing for a predetermined time or more in the operation verification; acquiring an appearance transistor state using the corresponding appearance cell state in the operation verification for each transistor; and calculating a test activity ratio of the transistor using the corresponding appearance transistor state for each transistor.

In a simulation step, based on information of a main surface shape of a transparent substrate and shape information of a mask stage of an exposure apparatus and using a deflection differential equation taking into account a twist deformation, height information at a plurality of measurement points is obtained by simulating a state where the transparent substrate is set in the exposure apparatus. Based on the height information obtained through the simulation, a flatness of the transparent substrate when it is set in the exposure apparatus is calculated in a flatness calculation step. Then, by judging in a selection step whether or not the calculated flatness satisfies a specification, the transparent substrate whose flatness satisfies the specification is used as a substrate for a mask blank.

A method of building optical proximity correction model comprises the following steps of collecting optical proximity correction data to a database from processes, determining an initial value X0, an end value Xn and a fixed step size h, calculating initial value slope coefficient according to the initial value X0, obtaining an initial optimal step size Y0 according to the initial value slope coefficient, obtaining a first additive value X1 according to the initial value X0 and the initial optimal step size Y0, repeating the steps, working out a second additive valueX2, a third additive value X3,..., till the end value Xn, fitting the initial value X0, the first additive value X1, the second additive value X2, the third additive value X3,..., till an n-1 additive value and the end value Xn. Through the above steps, as step size values can be regulated according to the slope coefficient worked out, regulation step number can be reduced and simulation time is shortened.

The invention provides a method for detecting whether a crystal oscillator circuit starts oscillation or not and a circuit structure. The method comprises the steps that a loop gain simulation method is adopted for setting the scanning frequency of a frequency generator, the parameter values of a loop capacitor, a loop inductor, a feedback resistor, a first load capacitor and a second load capacitor are given, the simulation process is started, and a loop gain curve is obtained from a common pin of the loop inductor, the feedback resistor and a crystal; then the parameter values of the feedback resistor, the first load capacitor and the second load capacitor are changed, the simulation process is started again, and a loop gain curve is obtained from the common pin of the loop inductor, the feedback resistor and the crystal; the process is repeated, and therefore whether the crystal oscillator circuit starts oscillation or not under each group of parameter values is detected fast. By means of the method for detecting whether the crystal oscillator circuit starts oscillation or not, whether the crystal oscillator circuit starts oscillation or not can be fast and effectively detected, the whole simulation time is short, few hardware resources are occupied, and the simulation result is reasonable.

The invention discloses a simulative navigation data generation method and a client. Specifically, the method is applied to a client equipped with a navigation tool, and the client has a display area. The method includes: starting the navigation tool of the client to conduct navigation simulation, and acquiring the navigation route; acquiring at least one segment information by segmentation of the navigation route; establishing an interpolation model on each segment route corresponding to the at least one segment information by means of variable speed simulation; inserting simulative navigation data into each segment route according to the interpolation model by means of interpolation; and outputting and displaying the simulative navigation data in the display area.

The invention discloses a time synchronization method in a system of an optical orthogonal frequency division multiplexing-based passive optical network (OOFDM-PON). The scheme comprises an optical line terminal (OLT) and an optical network unit (ONU), wherein the OLT comprises a laser, a modulator, an OFDM signal generating module and an optical multiplexer. The ONU comprises an optical demultiplexer, a time delay compensator, an optical detector and an OFDM receiving module. At the transmitting end of the OLT, optical signals for modulating optical OFDM signals and timing information are divided into two branches. The optical signals are divided into two branches after transmitted by optical fibers, wherein a timing signal is extracted from the branch for carrying the timing information by the optical detector after time-delay compensation, and the OFDM signals are accurately received at the receiving end of the ONU. The invention has the characteristics of simple design principle, easy realization, low cost and the like.

The invention discloses a distributed simulation method based on a TLM system model. Starting from the algorithm simulation of the TLM system modeling module (1), the entire algorithm simulation process is divided into several time periods as required, and the time-sharing state generation module (2 ) to generate a time-sharing state file, record important system state values ​​at the end of each time period, and distribute the loading module (3) to read the time-sharing state file and convert different state values ​​into different RTL simulation initial values, and the simulation result analysis module (4) Multiple time period simulations are performed in parallel according to different initial values, and the simulation results are distributed and comparatively analyzed by the simulation result analysis module (5) to complete the entire process of distributed simulation. This simulation method solves the problems of slow speed and many iterations of the traditional simulation method.