Patents by Inventor Srilata Raman

Srilata Raman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6209123
    Abstract: A method of automatically placing transistors of a folded transistor circuit for synthesizing rows of transistors in a semiconductor layout (172). First, an initial placement of transistors is generated (802). Next, a candidate move of transistors is selected (804). Then the change in cost of the placement resulting from applying the candidate move is evaluated (806). A decision is made to accept the candidate move based on the evaluation of its cost (808). If accepted, the move is performed (810) and the cost of the placement is updated (812). Finally, a decision to terminate the process is made (814).
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: March 27, 2001
    Assignee: Motorola, Inc.
    Inventors: Robert L. Maziasz, Mohankumar Guruswamy, Srilata Raman
  • Patent number: 6075934
    Abstract: A method for optimizing contact pin placement in an integrated circuit, wherein a netlist containing connectivity information, and placement information for a semiconductor circuit is read. Each net in the circuit is classified (510). Unblocked tracks are identified for each net in the circuit (512). All contact pins associated with nets having a power supply classification are placed according to a power supply location (513). The blockage for each remaining net is updated. Next, all contact pins for nets residing within a defined diffusion are placed (514) The blockage for each remaining net is updated. Next, all contact pins for nets residing in multiple defined diffusion areas are placed (515).
    Type: Grant
    Filed: May 1, 1997
    Date of Patent: June 13, 2000
    Assignee: Motorola, Inc.
    Inventors: Venkata K. R. Chiluvuri, Mohankumar Guruswamy, Srilata Raman, Robert L. Maziasz
  • Patent number: 6006024
    Abstract: A method for automatically selecting tie styles used during the horizontal placement of substrate and well ties. A linear order of tie styles is determined (2422). Ties are placed horizontally in the layout based upon an initial tie style (2424). Route and compact layout components (2426). If the layout has satisfied the tie coverage rules (2428) the tie style selection process is complete. Otherwise, contacts, vias and ties are added where possible (2430). If the layout has now satisfied the tie coverage rules (2432) tie style selection process is complete. If not, the next tie style is chosen from the linear order (2434). The process continues by placing (2424), routing and compacting components (2426) with the new tie style, until the cell satisfies the tie coverage rules.
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: December 21, 1999
    Assignee: Motorola, Inc.
    Inventors: Mohankumar Guruswamy, Daniel Wesley Dulitz, Andrea Fernandez, Srilata Raman, Robert L. Maziasz
  • Patent number: 5984510
    Abstract: A method for automatically synthesizing standard cell layouts(170) given a circuit netlist, a template describing the layout style and a set of process design rules (136) starts by numerating an ordered sequence of physical netlists from the logical netlist(138). Next, a netlist is selected from the ordered sequence of physical netlists (140). Components are placed according to the selected physical netlist (144). The components are routed to implement interconnections specified by the netlist (154). The components are compacted (156). A next netlist is selected from the ordered sequence of physical netlists. The steps of placing, routing and compacting the components are repeated. The layout with the smallest width is selected(166). Finally, ies, contacts and vias are added and notches filled (170) to improve yield and performance of the circuit.
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: November 16, 1999
    Assignee: Motorola Inc.
    Inventors: Mohan Guruswamy, Daniel Wesley Dulitz, Robert L. Maziasz, Srilata Raman, Venkata K. R. Chiluvuri, Andrea Berens
  • Patent number: 5987086
    Abstract: A method of interconnecting transistors and other devices in order to optimize area of a layout of a cell while honoring performance constraints (1502) and enhancing yield starts with a prerouting step (152) that routes adjacent transistors using diffusion wiring (1506), routes power and ground nets (1508), routes aligned gates (1510), routes all remaining aligned source/drain nets as well as any special nets (1512). Next, all of the remaining nets are routed using an area based router (1408). Nets are order based on time criticality or net topology (1602). A routing grid is assigned for all the layers to be used in routing (1604). An initial coarse routing is performed (1606). Wire groups are assigned to routing layers (1608). Routing is improved and vias are minimized (1610). A determination is then made whether the routing solution is acceptable (1612). If the routintg solution is not acceptable, the routing space is expanded and routing costs and via costs are modifyied to improve the routing solution.
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: November 16, 1999
    Assignee: Motorola Inc.
    Inventors: Srilata Raman, Mohankumar Guruswamy, Daniel Wesley Dulitz, Venkata K. R. Chiluvuri, Robert L. Maziasz