JPH0575294B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a programmable integrated circuit which has programmable wiring and which is programmed by a user to realize a desired circuit.

[Prior Art] Traditionally, devices have included programmable wiring, which the user can program at hand to freely interconnect elements and circuit elements built into a chip to realize a desired circuit. Programmable integrated circuits are known. One example of this is disclosed in Japanese Patent Application Laid-open No. 198919/1983. Conventional programmable wiring consists of switching matrices arranged at equal intervals vertically and horizontally, and multiple wiring elements connecting these switching matrices.The switching matrix uses programmable pass transistors to perform the switching. It was configured so that wiring elements connected to the matrix could be interconnected freely.

[Problems to be Solved by the Invention] However, in the programmable wiring of the programmable integrated circuit in the above-mentioned conventional technology, emphasis is placed on increasing the degree of freedom of the wiring, and switching matrices that enable interconnection between wirings are required. They have become complex, and when making long-distance connections within a chip, they must go through many switching matrices, and many pass transistors and other switching elements that delay the signal. This has been an obstacle to increasing the operating speed of the circuit that is being implemented.

The present invention was devised to solve the above problems, and provides a programmable integrated circuit that can prevent signal delays and improve operating speed when long-distance wiring is carried out within a chip using programmable wiring. With the goal.

[Means for Solving the Problems] The configuration of the programmable integrated circuit of the present invention for achieving the above object is as follows: In a programmable integrated circuit having programmable wiring, the programmable wiring connects a plurality of switching matrices and the switching matrices. and a plurality of wiring elements that connect between the wiring elements, and the switching matrix has a direct connection line that directly connects the wiring elements.

[Function] The present invention provides a direct connection line that does not pass through the switching elements that make up the switching matrix in the switching matrix that makes up the programmable wiring, and when distance connections within the chip are made programmably. By using long-distance wiring elements that are connected to the direct connection line, there are fewer opportunities for signals to pass through elements that delay them, increasing the operating speed of the intended circuit. .

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a circuit layout diagram of a programmable integrated circuit showing one embodiment of the present invention. This embodiment is an example in which the present invention is applied to a programmable integrated circuit configured such that input/output signals of a plurality of programmable logic elements can be freely interconnected using programmable wiring. 1 is a programmable logic element (hereinafter referred to as a
(abbreviated as PLE) and are arranged, for example, at equal intervals with spaces. 2-1, 2-2, 2-
3, . . . 2-N are switching matrices (hereinafter referred to as switching matrix 2 when explained representatively), and 3 is a plurality of wiring elements connecting these switching matrices 2. Switching matrix 2 is placed in the cross-shaped space between PLE1, and wiring element 3
are arranged vertically and horizontally in the space between PLE1.
Input signal line 1a and output signal line 1b of PLE1
are arranged so as to cross the wiring element 3, and can be connected to any line of the wiring element 3 by a switch element such as a programmable pass transistor using control bits similar to those described above.

Here, the configuration of the switching matrix 2 will be described. Switching matrix 2 (e.g. 2-
1) is a part of the wiring element 3 connected to it (for example, between 3-1 and 3-5, between 3-2 and 3-6)
between 3-12 and 3-16), direct connection lines 2-1a and 2- which directly connect wiring elements without using switch elements to freely interconnect wiring elements.
1b, 2-1c, and the remaining wiring elements 3-3, 3-4, 3-7, 3-8, 3-9 to 3
-11, 3-13 to 3-15, by programmable switch elements as in the past.
Configured so that they can be freely interconnected. For example, wiring element 3-5 connected by direct connection line 2-1a
By configuring the adjacent switching matrix 2-2 and subsequent ones to be connected by straight connection lines, it is possible to obtain an even longer direct wiring line.

The operation of the embodiment configured in this way will be described. The wiring lines of the wiring elements 3 which are connected by direct connection lines in the switching matrix 2 are used for long-distance connections because they do not go through elements that delay signals, such as switching elements. In order to connect this long-distance wiring line to the input/output signals of PLE 1, it may be necessary to arbitrarily connect it to other wiring elements 3, so the length of the direct wiring line formed above may also be It is preferable to prepare a variety of items. Wiring elements (for example, 3-8) that can be freely connected to other wiring elements 3 in each of the adjacent switching matrices 2 are used for short-distance connections by taking advantage of their degree of freedom. In this way, this embodiment can be realized using this programmable integrated circuit by forming a wiring line for long-distance connections in which signals rarely pass through delay elements, in addition to wiring elements for short-distance wiring. Improve the operating speed of the circuit.

Note that in the above embodiments, the circuit elements arranged on the chip are not limited to PLEs, and the effects of the present invention do not change even if they are various elements or arbitrary circuits. As described above, the present invention can be applied in various ways in line with its gist and can take various embodiments.

[Effects of the Invention] As is clear from the above description, according to the programmable integrated circuit of the present invention, a direct connection line that does not go through a signal delay element is provided in the switching matrix of the programmable wiring.
By making long-distance connections within the chip using long-distance and wiring elements connected to it,
Signal delays in programmable long-distance connections are reduced, and the operating speed of the circuit to be implemented can be improved.

[Brief explanation of the drawing]

FIG. 1 is a circuit layout diagram of a programmable integrated circuit showing one embodiment of the present invention. 2-1, 2-2,..., 2-N... switching matrix, 2-1a, 2-1b, 2-1c...
Direct connection line, 3, 3-1, 3-2,..., 3-
16...Wiring element.

Claims (1)

[Scope of Claims] 1. A programmable integrated circuit having programmable wiring, wherein the programmable wiring includes a plurality of switching matrices and a plurality of wiring elements connecting the switching matrices, and the switching matrix has the above-mentioned switching matrix. A programmable integrated circuit comprising a direct connection line directly connecting wiring elements, wherein the programmable wiring has long-distance wiring elements connected by the direct connection line.