Method and system for layout design of integrated circuits with a data transferring flow

• US 5,239,465 A
• Filed: 05/07/1991
• Issued: 08/24/1993
• Est. Priority Date: 10/11/1988
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hattori, Toshihiro, Miyamoto, Shunsuke, Miura, Chihei
• Primary Examiner(s): Kriess, Kevin A.
• Application Number:
  US07/700,042
• Time in Patent Office: 840 Days
• Field of Search: 364/488, 364/489, 364/490, 364/491
• US Class Current: 716/123
• CPC Class Codes: G06F 30/392 Floor-planning or layout, e.g. partitioning or placement

Abstract

As a basic connection information determined on the basis of a basic information determined in advance between logic elements by paying attention to the flow of data, the present invention includes a structure for transferring data from one data element to another data element, a structure for transferring data from one data element to a plurality of data elements and a structure for transferring data from a plurality of data elements to one data element, decides the sequence of unidimensional placement of sets of elements as the object of the flow of data inside a logic circuit on the basis of these structures, and automatically and quickly determine the initial placement positions of the sets of elements from the sequence thus decided.

Claims

1. A layout method performed by an automatic layout system, the method comprising the steps of:

deciding, in said automatic layout system, a plurality of placement sequences for respective sets of data system elements through which data flows inside a logic circuit to be laid out on the basis of basic connection information being preliminarily determined on the basis of a basic information among data system logic elements in accordance with a flow of non-control data through said data system logic elements;

deciding, in said automatic layout system, a second sequence which comprises said sets of data system elements in said logic circuit to be laid out, on the basis of connecting relations among the sets of data system elements, said connecting relations being determined in accordance with said flow of non-control data; and

,

deciding, in said automatic layout system, an initial placement positioning of each of said data system logic elements by determining an order of said data system logic elements in said second sequence.

2. The layout method according to claim 1, further comprising a step of deciding, in said automatic layout system, the plurality of placement sequences based on a first connection information as a structure for transferring data from one data element to another data element in a string of data system data elements, a second connection information as a structure for transferring data from one data system data element to a plurality of data system data elements and a third connection information as a structure for transferring data from a plurality of data system data elements to one data system data element.

3. The layout method according to claim 2, further comprising the steps of:

extracting said first, second and third connection information within the logic circuit; and

,

deciding, in said automatic layout system, a sequence of hierarchical placement of said sets of data system elements overlapping one another by giving highest priority to said first connection information among said first, second and third connection informations thus extracted.

4. The layout method according to claim 1, further comprising the step of deciding, in said automatic layout system, a placement sequence for said respective sets of data system elements which include at least one set of data description elements that express one datum by a plurality of data system elements or a set of processing elements which process altogether one datum by a plurality of data system elements.

5. The layout method according to claim 4, further comprising the step of deciding, in said automatic layout system, a placement sequence for said data system elements wherein each of said data system elements is an element corresponding to one-bit data, and wherein said set of data description elements include a group of latches and said set of processing elements include a selector.

6. The layout method according to claim 5, further comprising deciding the initial placement position of each of said data system elements so that the latches expressing data at the same bit position between the groups of said latches are placed adjacent to one another.

7. The layout method according to claim 2, further comprising a step of deciding, in said automatic layout system, a plurality of placement sequences on the basis of a register, a latch, a gate, an inverter and a group corresponding to said basic connection information.

11. The layout method according to claim 1, further comprising a step of identifying said flow of non-control data by identifying data elements among said system elements.

12. The layout method according to claim 11, wherein said identifying step includes identifying said data elements by attribute information thereof.

13. The layout method according to claim 1, further comprising a step of replacing cells in said data system elements in accordance with a group information in control information for said data system elements.

8. A layout system in an automatic layout system comprising:

means for deciding a plurality of sequences in the respective sets of data system elements through which data flows inside a logic circuit to be laid out on the basis of basic connection information determined on the basis of a basic information among data system logic elements in accordance with a flow of non-control data through said logic elements;

means for deciding a second sequence which comprises said sets of data system elements in said logic circuit to be laid out, on the basis of connecting relations among the sets of data system elements, said connecting relations being determined in accordance with said flow of non-control data; and

,

means for deciding an initial placement positioning of each of said data system logic elements by deciding an order of said data system logic elements in said second sequence.

9. The layout system according to claim 8, wherein said basic connection information includes a first connection information as a structure for transferring data from one data element to another data element in a string of data system data elements, a second connection information as a structure for transferring data from one data system data element to a plurality of data system data elements and a third connection information as a structure for transferring data from a plurality of data system data elements to one data system data element.

10. The layout system according to claim 9, further comprising:

means for extracting said first through third connection informations from within the logic circuit; and

means for deciding a sequence of hierarchical placement of said sets of data system elements overlapping one another by giving highest priority to said first connection information among said first through third connection informations thus extracted.

14. A placement sequence method performed by an automatic layout system, the method comprising the steps:

reading data system logic elements, used for logical data transfer, from a file;

generating basic connection information of the data system logic elements based on a basic relational logic criterion;

hierarchically grouping sets of the data system logic elements based on a basic structure of a predetermined logical data flow priority, the grouping including in descending order of grouping priority;

a data sequence relation grouping, a data fork relation grouping, and a data join relation grouping;

determining, in said automatic layout system, a one-dimensional placement sequence of a first set of data system logic elements based on a predefined decision rule in such a manner that logic data flows serially therethrough the first set of data system logic elements;

determining, in said automatic layout system, a two-dimensional placement sequence from the one-dimensional placement sequence such that the first set of data systems logic elements are inter-mixedly arranged in data cells in a first direction transverse to a second direction of the one-dimensional placement sequence and such that the data cells have corresponding lengths; and

,

laying out the integrated logic circuit system according to the two-dimensional placement sequence and interconnecting the integrated logic circuit according to said basic connection information.