JPH0529461A - Wiring method inside lsi - Google Patents

Abstract

PURPOSE:To provide a wiring method inside LSI capable of effectively using regions by flexibly modifying the initial program in relation to the title wiring method of LSI. CONSTITUTION:This wiring method inside LSI is devised so that the wiring region 10 inside an LSI may be divided into multiple small regions 12-1, 12-2 to set up the existence and positions of the temporary terminals 20, 22 in the small regions 12-1, 12-2 in case of global routing while flexibly modifying said existence and positions of the temperary terminals 20, 22 in the small regions 12-1, 12-2 in case of detailed routing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring system inside an LSI. In recent years, the number of elements integrated in one LSI chip has increased exponentially, and the amount of wiring between these elements has also increased dramatically. Due to the enormous amount of wiring, it is becoming difficult to wire all areas at one time due to functional restrictions of the computer, and the entire chip is divided into several small areas for wiring. I often do it.

In the case of dividing into small areas, first, the state in which the wiring is running as a whole is checked, and each wiring net is assigned to the small area. Since this allocation operation is calculated more roughly than the wiring for each small area that is subsequently performed, the area for the wiring may become insufficient or redundant later.

Generally, it is common to perform allocation operations with a margin so that the area will not run out.
In order to improve the integration degree of the LSI chip, it is desired to reduce or eliminate this extra area.
On the contrary, since the extra area is too small, the area may be insufficient and wiring may be impossible. Therefore, in the present invention, by dynamically changing the allocation operation during calculation,
The purpose is to use the area effectively.

[0004]

2. Description of the Related Art When a large LSI chip is divided into several small areas for wiring, the wiring extending over a plurality of small areas is located at the outermost periphery of each small area (border between adjacent small areas). A virtual terminal called a temporary terminal is often set.

[0005]

After the initial setting, the temporary terminal is usually not changed during the wiring of each small area. Therefore, in order to ensure that the wiring in each small area can be performed in the small area, it is common to set a little extra when estimating the size of the small area. There were cases where most of the area was left over. Therefore, when manufacturing a higher density LSI chip, it is necessary to reduce or eliminate the extra area.

On the contrary, since the extra area is too small, there is a case where the area becomes insufficient and wiring becomes impossible. Therefore, an object of the present invention is to provide a wiring system inside an LSI that can effectively use an area by dynamically changing an initial plan.

[0007]

According to the present invention, a wiring area (10) inside an LSI is divided into a plurality of small areas (12-1, 12-).
2) and divide it into small areas (12-1,
The presence and position of the temporary terminals (20, 22) are set in 12-2), and the small areas (12-1, 12-2) are set during detailed wiring.
It is characterized in that the presence or absence and the position of the temporary terminals (20, 22) are dynamically changed.

[0008]

The operation of the present invention will be described with reference to FIG. FIG. 1 shows a wiring system according to the principle of the present invention. In the figure, a solid line shows a region currently being wired, and a dotted region shows a region which is not yet wired and whose size can be changed. In the region, the transistor pattern,
Other wiring and the like are omitted.

First, FIGS. 1A and 1B show a case where an extra area can be deleted. In FIG. 1 (A),
The wiring area 10 inside the LSI includes two small areas 12-1,
12-2, and the small area 12-1 is divided into terminals 14 and 1
Have six. These terminals 14 and 16 should be connected to each other, but both terminals 1
Since the other wiring 18 exists between 4 and 16, both terminals 1
4 and 16 cannot be connected by a straight line wiring. Therefore,
Between the small area 12-1 and the small area 12-2, the temporary terminal 20,
22 is set and both terminals 1 are used by using the small area 12-2.
4 and 16 were connected by wiring 24.

However, when detailed wiring was performed in the small region 12-1, it was found that the wiring 18 did not exist between the terminals 14 and 16. Therefore, as shown in FIG. 1B, the temporary terminals 20 and 22 are deleted and both terminals 14 and 1 are removed.
6 is connected by a straight wiring 26. Thus, the extra area 12-1a and the small area 12-2 in the small area 12-1 are included.
The extra area 12-2a in the
And the small area 12-2 is reduced as a whole.

As described above, in FIGS. 1A and 1B, the small area 12-2 is used for rough planning,
It was planned to connect both terminals 14 and 16 in the small region 12-1 with the wiring 24, but since both terminals 14 and 16 could be connected with the straight wiring 26 during the detailed wiring, the temporary terminal 20 ,
22 is no longer necessary, and the small areas 12-1 and 12-2 are reduced as a whole.

Next, FIGS. 1 (C) and 1 (D) show a case where a missing area is added. In FIG. 1 (C),
Both terminals 14, 16 in the small area 12-1 should be connected to each other and both terminals 14, 16 will be used during rough planning.
Were to be connected by the wiring 28 in the small area 12-1. However, when detailed wiring is performed in the small area 12-1, another wiring 3 is provided between the terminals 14 and 16.
0 and 32 exist, and both terminals 14 and 16 are connected to the small area 12-1.
The internal wiring 28 made it impossible to connect.

Therefore, as shown in FIG. 1D, the temporary terminals 34, 3 are provided between the small area 12-1 and the small area 12-2.
Set 6, 38, 40 and use the small area 12-2,
Both terminals 14 and 16 are connected by a wiring 42. This allows
The small areas 12-2 are increased by the extra areas 44 and 46, but the terminals 14 and 16 are reliably connected.

As described above, in FIGS. 1C and 1D, both terminals 14 and 16 are arranged in the small area 1 in the rough planning.
It was supposed to be connected by the wiring 28 in 2-1.
Since it was not possible to connect both terminals 14 and 16 with the wiring 28 in the small region 12-1 during the detailed wiring, the provisional terminals 34, 36, 38 and 40 are set to connect both terminals 14 and 16. The connection is made by the wiring 42, so that the terminals 14 and 16 are surely connected.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows a wiring system inside the LSI.

In FIG. 2, the wiring area 10 inside the LSI is shown.
Are divided into five small areas 12-1 to 12-5, and the small areas 12-1 to 12-5 have terminals 44-1 to 4-5, respectively.
44-5 is set. Small areas 12-1 and 12-2
Between the small areas 12-2 and 12-3, and the small area 12
-3 and 12-4 and between the small areas 12-4 and 12-5, temporary terminals 46, 48, 50 and 52 are set, respectively, and the temporary terminals 46, 48 and 50 are set. , 52 are used to connect the terminals 44-1 to 4-4 in the small areas 12-1 to 12-5.
4-5 are connected by a wiring 54.

Extra areas 12-1a and 12-2a are set in the small areas 12-1 and 12-2, respectively.
I try not to run out of space for wiring.
Then, when connecting the two terminals 14 and 16 in the small area 12-2, the provisional terminals 20 and 22 were set and both terminals 14 and 16 were connected by the wiring 24 in the rough plan. Since the terminals 14 and 16 can be connected by the linear wiring 26 in the small area 12-2, the temporary terminals 20 and 22 are deleted (see also FIGS. 1A and 1B). .

When the two terminals 14 'and 16' are connected in the small area 12-4, both terminals 14 'and 16' are connected by the wiring 28 in the small area 12-4 according to a rough plan. Although it was planned to be done, there are cases where both terminals 14 'and 16' cannot be connected by the wiring 28 in the small region 12-4 with the detailed wiring. In this case, as shown in FIG.
As shown in (D), a temporary terminal is set and the small area 12
Wiring is performed using a region outside -4. It should be noted that the area outside the small area 12-4 (the area between the solid line and the dotted line in FIGS. 1C and 1D) is considered to be infinitely large in number.

It is considered that the wiring in the area outside the given area can be all ignored. Prior to wiring, it is convenient to divide the region into a region where many terminals are concentrated and a region dedicated to wiring where there are no terminals, so that the size of the region dedicated to wiring can be freely changed.

The position of the temporary terminal does not have to be set at the outermost periphery of the area, but may be set inside the area.
For example, a temporary terminal for power supply may be set inside the area. At this time, it is necessary to surely wire the temporary terminals inside the region to the temporary terminals in other portions or to the other terminals.

Next, FIG. 3 shows a flow chart of a wiring system according to an embodiment of the present invention. Step 10
A cell is arranged at 0, and the flow of the whole wiring is decided at step 102 to make a rough plan. In the conventional case, the process proceeds from step 102 to step 104, the detailed wiring is performed according to the rough plan, and when the area is insufficient, the process is stopped.

On the other hand, in the case of the embodiment of the present invention,
From step 102 to step 106, detailed wiring is performed according to a rough plan. When the extra area can be simplified, it is simplified (in the case of FIGS. 1A and 1B). On the contrary, when the area is insufficient, the rough plan is changed (in the case of FIGS. 1C and 1D).

[0023]

As described above, according to the present invention,
The wiring area can be effectively used by dynamically changing the plan for the temporary terminals in the small area. Further, according to the present invention, as compared with the conventional wiring method, the calculation of the wiring allocation to each small area can be performed easily and reliably. In addition, in the conventional wiring method, since the temporary terminal initially set is not changed (or cannot be changed), the position of the temporary terminal must be precisely set in a rough plan. Since the presence or absence and the position of the temporary terminal can be changed later during the detailed wiring, it is not necessary to precisely set the position of the temporary terminal during rough planning. Further, in the present invention, since the extra area can be deleted, the density of the LSI chip can be increased as compared with the conventional wiring method.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a wiring system according to the principle of the present invention,
(A) and (B) show examples in which temporary terminals are no longer needed,
(C) and (D) show an example in which a temporary terminal is required.

FIG. 2 is an explanatory diagram of a wiring system inside an LSI.

FIG. 3 is a flowchart of a wiring method according to an exemplary embodiment of the present invention.

[Explanation of symbols] 10 ... Wiring area 12-1, 12-2 ... Small area 14, 16 ... Terminal 20, 22 ... Temporary terminal 24 ... Wiring 26 ... Wiring 28 ... Wiring 34, 36, 38, 40 ... Temporary terminals 42 ... Wiring

Claims (3)

[Claims] 1. A wiring area (10) inside an LSI is divided into a plurality of small areas (12-1, 12-2), and the small areas (12-1, 12-2) are provisionally divided in rough planning. Terminal (20,
22) presence / absence and position are set, and the presence / absence and position of the temporary terminals (20, 22) in the small regions (12-1, 12-2) are dynamically changed during detailed wiring. Wiring method inside the LSI. 2. The wiring method inside the LSI according to claim 1, wherein a temporary terminal (2) is provided in a small area (12-1) at the time of rough planning.
0, 22) was set, but a small area (1
2-1) Wiring method inside LSI characterized by deleting the temporary terminals (20, 22). 3. The wiring method inside the LSI according to claim 1, wherein a temporary terminal is not set in the small area (12-1) during rough planning, but a small area (12-1) is set during detailed wiring. ), The temporary terminals (34, 36, 38, 40) are set to the wiring system inside the LSI.