Synopsys, Inc.

Neeraj Kaul

Balkrishna R Rashingkar

Douglas Chang

Peiqing Zou

Wei-Chih Tseng

Anthony Y Tseng

One embodiment of the present invention provides a system that scales an I/O-cell placement during die-size optimization. During operation, the system starts by receiving an initial die-size for a die and an initial I/O-cell placement for a set of I/O cells. The system also receives a target die-size for the die. The system then determines die-size changes between the initial die-size and the target die-size. Next, the system identifies available spaces between the set of I/O cells in the initial I/O-cell placement. The system subsequently scales the initial I/O-cell placement based on the identified available spaces and the die-size changes to obtain a new I/O-cell placement which fits in the target die-size.

Method and apparatus for scaling I/O-cell placement during die-size optimization

One embodiment of the present invention provides a system that computes a routability estimation across a collection of local routing regions associated with a circuit layout. This system first selects a first local routing region associated with a route overflow, wherein a respective local routing region is associated with an estimation of a number of route overflows for routing layers in a region of the circuit layout. Furthermore, a respective routing layer is associated with a preferred direction variable D. Next, the system transfers an overflow value k in direction d away from an overflowing routing layer for the first local routing region to a second local routing region, which has the capacity to handle an overflow of k or more routes in a direction d. Finally, the system computes a global routability estimation as a function of a global overflow cost and an adjacent overflow cost.

Method and apparatus for computing a detailed routability estimation

A system that routes nets within an integrated circuit. During operation, the system receives a representation for the integrated circuit, which includes block boundaries for physical partitions of the IC generated from a hierarchical design placement of the integrated circuit. The system then classifies each net in the integrated circuit based on the location of pins associated with the net. Next, the system generates routing constraints for each net based on the classification of the net and applies a feedthrough constraint to the physical partitions to restrict nets from feeding through physical partition boundaries. Finally, the system routes each net using the routing constraints for the net and the feedthrough constraints for the physical partitions. This routing is performed based on these block boundaries prior to finalizing the hierarchical design placement, thereby facilitating early detection of congestion or timing violations which can be corrected early in the design process.

Growing community of inventors

Fremont, CA, United States of America

Neeraj Kaul