JPS6381569A - Design system for microcomputer - Google Patents

Abstract

PURPOSE:To develop a microcomputer conforming to the requirements of user in a short period by forming a microprocessor section, a peripheral circuit and a memory circuit as modules having nearly the same lateral width and connecting the modules by a bus. CONSTITUTION:Plural types different in storage capacity are prepared for memory modules such as a mask ROM module, an EPROM module, an EEPROM module and a RAM module. Then the layout of each element and wiring is designed so that the lateral width of each module expanded into the circuit pattern is nearly constant. Then the wiring is applied so that input/output terminals of each circuit, that is, the entrance/exit of the signal are arranged on one side of each module at an equal interval or with regularity. Then the arrangement of the modules selected by the user is decided. In this case, the length of the wiring (bus) connecting the modules is designed as short as possible. Thus, the user can develop a microcomputer conforming to its requirements in a short period.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technology particularly effective when applied to a semiconductor integrated circuit design technology and a semiconductor integrated circuit layout method, such as ASIC (appH, cation
5specific integrated circus
This invention relates to techniques that are effective for use in the design method of microcomputers compatible with UIT.

[Conventional technology] Conventionally, microcomputers such as single-chip microcomputers have been made compatible with the basic microcomputer by enhancing some of its functions or changing the capacity of its built-in memory. Although a number of products were offered one after another, all of them were only offered as general-purpose LSIs (Large-Scale Integrated Circuits).

[Problems to be solved by the invention] However, in recent years, even in the field of microcomputers, there has been a strong demand for microcomputers called ASICs (application-specific LSIs) that have functions that meet the needs of users. There is.

Microcomputers having functions that meet the needs of each user may have different configurations of peripheral circuits, but the configuration of the main microprocessor section may be the same. However, due to the nature of LSI chips, the entire chip is made into a rectangular shape, so even if the microprocessor has the same functions, the microprocessor part is surrounded by peripheral circuits, as shown by diagonal lines in Figure 5 (A) to (D). the shape of,
The shape and layout must be changed according to the arrangement.

Therefore, even if existing technology is used as is, there are problems in that it takes a long time to develop a microcomputer that meets user requirements, and dead space is created on the LSI chip where no circuit is formed. .

An object of the present invention is to develop a microcomputer that meets user requirements in a short period of time and to provide it at a low cost.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] Representative inventions disclosed in this application will be summarized as follows.

In other words, the microcomputer is divided into multiple functional blocks, and each functional block has multiple circuits with different functions and capacities prepared as modules.
The horizontal length of each module is designed in advance to be approximately equal, the user is asked to select the desired function from among the prepared modules, and once the modules have been determined, they are simply stacked. A microcomputer can be designed by arranging the modules as shown in FIG.

[Operation] According to the above-mentioned means, since each functional block is modularized, it becomes possible to connect the modules by automatic wiring, and once the desired modules are determined, they can be simply arranged in a stacked manner. It is possible to easily configure a microcomputer with the desired functions using the above-described method, thereby shortening the development period for an ASIC-compatible microcomputer and achieving the above-mentioned objectives of not creating dead space on an LSI chip. can.

[Embodiment 1] An embodiment in which the present invention is applied to a single-chip microcomputer will be described below with reference to the drawings.

In this embodiment, each functional block constituting a single-chip microcomputer is prepared as a module. The types of modules can be broadly divided into CP
There are three: U module, peripheral module, and memory module. Among these, the peripheral modules can be further classified into serial communication interface modules, timer modules, A/D converter modules, DMA control modules, and the like.

In addition, as memory modules, mask ROM modules, EPROM modules, EEPR○MEPROM
Possible modules include modules.

Table 1 shows an example of the classification of each module and its type.

As shown in Table 1, in this example, the CPU
As a module, 4-bit CPU, 8-bit CPU
A 16-bit CPU and a 32-bit CPU are available.

Serial communication interface modules come in clock synchronous and clock asynchronous types, and timer modules include 8-bit and 16-bit ones, as well as reload timers, free-running counters, input capture registers, and output conveyor registers. Each one has what they have.

As an A/D converter module, 8-bit or 1
There are DMA controller modules with different division capabilities, such as 2-bit, and DMA controller modules, such as those capable of high-speed transfer and those for low-speed transfer.

Furthermore, a plurality of types of memory modules such as mask ROM modules, EP ROM modules, E EP ROM modules, and RAM modules are prepared, each having a different storage capacity.

In this embodiment, the width of each module is set to be approximately constant when the circuit pattern is developed in advance.
The layout of each element and wiring is designed.

In this case, among the various modules mentioned above, especially memory and CP
U has a regular structure, and the width of the circuit is often determined depending on the number of bits. Therefore, first, the width of the module is determined for these circuits, and then the width of the module is determined based on the number of bits. Peripheral modules are designed with high flexibility in layout design so that the widths of each module are approximately equal.

Further, in the module of this embodiment, the wiring is routed so that the input/output terminals of each circuit, that is, the signal inlet/outlet are lined up on one side of the module at equal intervals or with regularity.

Then, a table such as Table 1 showing a list of modularized functions is provided to the user.

Have them select the desired function (or module) from the table. Then, the manufacturer determines the arrangement of each selected module. At this time, in order to shorten the length of the wiring (bus) connecting each module as much as possible, as shown in Figure 1, the CPU module 1
The arrangement order is determined so that the module is positioned at the center of the other modules 2, 3, 4, . . . .

Then, the input/output terminals of each module are arranged in a horizontally elongated state so that they are concentrated on one side, and the modules are stacked vertically. Then, these are sent to a system that performs automatic wiring design, and each module row 1, 2, 3...・・・
A bus BUS is provided on the - side of . . . to connect each module. However, when each functional block of a single-chip microcomputer is modularized, it may not be possible to completely match the width of each module. In that case, as shown in Figure 2, align one side of each module with the bus installation side, that is, arrange the input and output terminals of each module in a straight line, and then perform automatic wiring design. do it like this.

Furthermore, when the selected modules are stacked, for example, if the height is more than twice the width of the module, as shown in Figure 3, each module 1, 2. Determine the sequence of 3... At this time, the input/output terminals of each module 1, 2, 3, etc. should face the bus BUS, that is, the modules 1 to 5 in the left column should have one side with the input/output terminal on the right. Furthermore, the modules 6 to 9 in the right column are arranged with one side where the input/output terminals are located on the left. This kind of operation.

This can be easily achieved by rotating the module 180 degrees.

If the widths of the modules vary widely, a plurality of smaller width modules A and B or E and F can be arranged in a row, as shown in FIG. In this case, by arranging the bus around the module group, it is possible to easily connect the bus BUS and each module as shown by the arrows in the figure.

According to the design method of the above embodiment, a microcomputer is divided into a plurality of functional blocks, and each functional block has a plurality of circuits with different functions and circuits prepared as modules, and the horizontal length of each module is The modules are designed in advance so that they are approximately equal, the user is asked to select the desired function from among the prepared modules, and once the modules have been determined, they are arranged so that they are simply stacked. Moreover, since a bus area is provided on the negative side to connect each module, it is possible to connect the modules by automatic wiring, and once the desired modules are determined, they can be easily arranged by simply stacking them. By being able to configure a microcomputer with desired functions, it is possible to shorten the development period for ASIC-compatible microcomputers, minimize dead space on LSI chips, and provide inexpensive chips. .

The various modules are formed to be long in the horizontal direction and are stacked vertically, which prevents the chip shape from becoming particularly long in one direction. A nearly square chip shape can be easily realized.

The microprocessor part of each module is placed approximately in the middle of the other modules, so the distance from the CPU to each module is shorter than if the CPU were placed at the edge of the chip. Due to the shortening effect, the wiring length of the entire circuit can be shortened.

Even if the widths of each module are slightly different, the ends of the modules are arranged in a straight line on the bus installation side, which minimizes the distance between the bus and each module, reducing the wiring length. It's short enough.

Since the width of each module is determined based on the memory circuit module, the width of each module can be made uniform by designing the peripheral module later, which has relatively high flexibility in element layout design. It has the effect of being easy.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, the types of modules shown in Table 1 are just an example, and instead of preparing CPU modules by classifying them into bit numbers, or in addition to this, there are also those with rich and small instruction sets even though they have the same number of bits. They may be prepared separately, or may have different operation modes.

In the above explanation, the invention made by the present inventor was mainly applied to a single-chip microcomputer, which is the background field of application. If provided, it can be used by the public.

[Effects of the Invention] The effects obtained by typical inventions disclosed in this application are briefly explained below.

In other words, a microcomputer that meets user requirements can be developed in a short period of time and can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the layout of a single-chip microcomputer when the present invention is applied. FIG. 2 is an explanatory diagram showing a layout example of an application of the present invention. FIG. 4 is an explanatory diagram illustrating an example of the arrangement of microprocessor sections in a layered structure, illustrating a third application example of the present invention. 1...CPU module, 2-9...Peripheral module or memory module, 13Us...ノ(
space area.゛・5-1'' Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 5

Claims (1)

[Claims] 1. A plurality of microprocessor sections, peripheral circuits, and memory circuits are prepared as modules each having approximately the same width, and a desired module is selected from among them and assembled into a single module. A design method for a microcomputer characterized by arranging modules along a direction, providing a bus area on the side thereof, and connecting each module by a bus. 2. The microcomputer design method according to claim 1, wherein the modules are formed to be elongated in the horizontal direction and arranged so as to be stacked in the vertical direction. 3. Among the above modules, the microprocessor section is
3. A design system for a microcomputer according to claim 1, wherein the microcomputer is arranged approximately in the middle of the arrangement positions of other modules. 4. Claims 1 and 2, characterized in that when the widths of the modules are slightly different, the ends of the modules are arranged in a straight line on the bus installation side. , or the microcomputer design method described in Section 3. 5. The microcomputer according to claim 1, 2, 3, or 4, wherein the width of each module is determined based on the memory circuit module. design method.