Technical Field

The present invention relates to a coprocessor control system having a host processor and a coprocessor, and more particularly to a coprocessor control system for reducing the burden of data transfer which a host processor effects with a coprocessor.

Background Art

To speed up a processing time, microprocessor systems widely employ a coprocessor control system which uses a coprocessor to lessen the burden of complex arithmetic processing operation on a host processor, which operation would require a long processing time if carried out by a microprocessor.

Such a coprocessor is sold in the market as a dedicated chip, and employed to reduce the burden on a host processor for thereby allowing the host processor to speed up its processing operation.

A control system such as a robot control apparatus has to execute a complicated arithmetic processing sequence on a on-line basis at all times. In such a control system, processing operation for transferring arithmetic processing commands to be executed by a host processor and data is required at all times and at high speed. If a command and data are transferred to a coprocessor in each arithmetic processing step, then it is difficult to perform actual robot control with accuracy.

Disclosure of the Invention

It is an object of the present invention to provide a coprocessor control system for reducing the burden of data transfer which a host processor effects with a coprocessor.

In order to solve the aforesaid problems, there is provided in accordance with the present invention a coprocessor control system having a host processor and a coprocessor, comprising a program memory directly accessible by said coprocessor, and a common RAM accessible by said host processor and said coprocessor, the arrangement being such that said host processor writes an arithmetic command to be executed and data into said common RAM, said coprocessor reads said arithmetic command and said data, effects arithmetic operation using said program memory, and writes the result of the processing operation on said arithmetic command into said common RAM, and said host processor reads said result of the processing operation.

The coprocessor has its own program memory. The host processor writes a plurality of arithmetic processing steps to be executed and data required thereby into the common RAM, and notifies the coprocessor of the writing operation. The coprocessor then reads the arithmetic processing steps and data, effects necessary arithmetic processing operation, writes the result of the arithmetic processing operation, and notifies the host processor of the writing operation. Then, the host processor can read the result. Since it is not necessary to transfer a command and data in each arithmetic processing step, the burden on the host processor is lessened.

Brief Description of the Drawings

FIG. 1 is a block diagram of the arrangement of an apparatus for carrying out the present invention.

Best Mode for Carrying Out the Invention

An embodiment of the present invention will hereinafter be described in specific detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment according to the present invention. Denoted in FIG. 1 at 1 is a host processor, 2 a memory storing a program, etc., to be executed by the host processor 1, and 3 an interface for transmitting signals to and receiving signals from an external device. The host processor 1, the memory 2, and the interface 3 are connected to a system bus 11.

A coprocessor ₄ for executing complex arithmetic processing steps is connected, by a local bus 12, to a program memory 6 used by the coprocessor 4 and a common RAM 5 for transferring arithmetic commands and data therefor to and from the host processor 1. The system bus 11 and the local bus 12 are connected to each other through a buffer 13.

Operation of the embodiment shown in FIG. 1 will be described below. The host processor 1 writes necessary arithmetic processing steps and data required thereby into the common RAM 5. For example, in controlling a robot, the following arithmetic processing step is required on a real-time basis in order to drive a number of movable parts with a plurality of servomotors and control the servomotors:Where Y1 ~ Yn are answers to be sought, A11, A12 ... Ann, and X1 ~ Xn are data required, A11 , A12 ... Ann in particular being coefficients including trigonometric functions. Therefore, the host processor 1 writes a command for the above matrix arithmetic operation and the data A11 , A12 ... Ann and X₁ ~ Xn into the common memory 5, and notifies the coprocessor of the writing operation.

In response to the notification, the coprocessor performs the above matrix arithmetic operation according to an arithmetic processing program stored in the program memory 6, writes the answers _Yi - Yn into certain predetermined addresses in the common RAM, and notifies the host processor 1 of the writing operation.

When the host processor 1 is notified of the completion of the arithmetic processing operation from the coprocessor 4, the host processor 1 reads out the answers, thus completing the necessary processing operation.

As described above, since the host processor ₁ is not required to transmit and receive an arithmetic command and data in each arithmetic processing step, but can process commands and data in a bunch, the burden on the host processor 1 is reduced. Therefore, the system of the invention can be used in an apparatus, such as a robot control apparatus, which is required to process a number of complex arithmetic operations at high speed on a real-time basis.

While a matrix arithmetic operation has been illustrated above by way of example, the present invention is not limited to the illustrated example, but is applicable to arithmetic processing steps that can be put together in a bunch dependent on a system to be controlled.

With the present invention, as described above, inasmuch as the coprocessor has the common RAM for transferring information between the program memory and the host processor, the host processor enables the coprocessor to process arithmetic operations in a bunch. The present invention is useful for processing complex arithmetic operations at high speed on a real-time basis as in a robot control apparatus.