摘要:
A computer implemented process for the automatic creation of integrated circuit (IC) geometry including a multiple pass process flow using multiple passes of direct timing driven placement after a first pass of non-direct timing driven placement. First, a high level description of the circuit design may be synthesized. Next, a non-direct timing driven placement process may place the design. Then the placed design may be routed. Alternatively, routability may be estimated. After routing, a modified design may be resynthesized. The resynthesized design may then be placed according to a direct timing driven placement process. This sequence may be repeated several times.
摘要:
A method and system of constrained optimization with linear constraints to remove overlap among cells of an integrated circuit. A coarse placement using well known methods may provide an initial placement of cells. Overlapping cells are separated. Any cell moved to its initial placement may be fixed so as not to be moved during subsequent placements. A plurality of linear inequalities representing allowable placements of a plurality of cells of a layout is generated. An objective function measuring cell movement subject to the constraints of the plurality of inequalities is minimized. The objective function minimizes cell movement from the initial cell placement. In this novel manner, large and small cells may be automatically simultaneously placed, deriving speed and quality advantages over prior art methods.
摘要:
A method and system for the simultaneous placement of large and small cells in an electronic circuit. A coarse placement using well known methods may provide an initial placement of cells. Cells meeting a size criteria may be selected for further processing. An optimum cell orientation may be determined. An optimum axis of movement for separation may be determined. Overlapping cells may be separated and their positions may be optimized in both horizontal and vertical directions. Any cell moved from its initial placement may be fixed so as not to be moved during subsequent placements. This process may be repeated for cells meeting a new, generally smaller, size criteria. A well known detailed placement process may finalize a design. In this novel manner, large and small cells may be automatically simultaneously placed, deriving speed and quality advantages over prior art methods.
摘要:
A method and system for the quick placement of electronic circuits using orthogonal one dimensional placements. All circuits of a design may be placed in a linear dimension to obtain a first placement. Next, those same circuits may be placed in a second linear dimension, orthogonal to the first dimension, in order to obtain a second placement. Finally, a two dimensional placement for the circuits may be created by selecting for each circuit element a first coordinate from the first placement and a second coordinate from the second placement.
摘要:
Computer based images are normally provided in the form of large amounts of data on a pixel by pixel basis. Method and apparatus (25) are disclosed for converting this pixel based data (7,8,9-16,17) to spline based data (FIG. 5) wherein the characteristics present in the pixel based data are substantially retained in the spline based version of the image.
摘要:
A method and apparatus that displays a “delay chart” on a display screen, using a variety of user-selected formats and representing delays of a circuit being debugged. These formats include right-to-left and left-to-right displays. The displays can optionally have duplicative paths merged and zero delay paths removed. The invention also allows the designer to select various parts of the delay chart and then automatically highlights related portions of HDL code for the circuit (which also is displayed on the display screen). Conversely, the designer can select portions of the HDL code and the invention will automatically highlight related portions of the delay chart. Thus, the designer can easily determine which parts of the HDL caused large delays in the circuit being designed and can easily change those parts of the HDL in an attempt to obtain more desirable timing.