Resources Contact Us Home
Logic circuit generating method and apparatus

Image Number 3 for United States Patent #5745373.

A logic circuit generating method and apparatus generating logic circuits of a circuit system by minimizing the fan-out count of cells or cell macros constituting information specific to the circuit system. According to the method, a Boolean expression and the polarities of its input/output variables are input from a design master file of the apparatus. The Boolean expression is then transformed into a two-branch tree composed of nodes represented by the logical operators of that expression. In the two-branch tree, the nodes representing a parent and a child logical operator are converted into a single node, whereby a multiple-branch tree is generated. That is, a plurality of gates are connected to a single net, or signal line. A cell library is referenced so that cells are assigned initially to the multiple-branch tree thus obtained. The initial cell assignment is performed preferentially starting from the cell whose fan-out count is the largest. This is done to minimize the number of loads represented by the assigned cells (i.e., the number of cells connected to the output net). The number of gate stages is then evaluated. The stage count is minimized by reassigning the cells. Finally, the acquired gate logic is output to the design master file.

  Recently Added Patents
Wideband antenna
Semiconductor device with an amorphous semi-insulating layer, temperature sensor, and method of manufacturing a semiconductor device
Pizza stone
Analog-to-digital converter control using signal objects
Front face of a vehicle wheel
Interlock apparatus for vacuum circuit breaker
Attribute information providing system
  Randomly Featured Patents
Energetic azido eutectics
Latching mechanism for rear gate of dump vehicle with automatic tilt release
Electrical adapter
Thin film EL panel
Water-injection diesel engine
Semiconductor element, method for manufacturing the same, and mounting structure having the semiconductor element mounted thereon
Dicentra plant named `Spring Magic`
Hybrid structure of multi-layer substrates and manufacture method thereof
Reflection type photoelectric switch
Heat treatment of titanium alloys