JP3323430B2 - Communication control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control device used by connecting to an expansion bus of a personal computer.

[0002]

2. Description of the Related Art For example, IS
A function expansion bus such as an A bus is provided, and a communication control device is a typical external device connected to the bus and used.

FIG. 5 shows a schematic configuration example of a conventional communication control device. The communication control device 100 shown in FIG. 1 includes a built-in computer 11, a ROM 12, a RAM 13, a functional device 14 for executing a communication process, interrupt generation logics 15, 16 and a bidirectional access RAM 17, which are interconnected by a bus B1. In addition, while being autonomously operated by the built-in computer 11, by being connected to an expansion bus B2 of an external computer 200 such as a so-called personal computer, a command / response (command and its command) is exchanged with the external computer 200. ) And the transmission and reception of data.

In this case, the transfer of the command / response and the transmission / reception data is performed through the bidirectional access RAM 17. The bidirectional access RAM 17 has two access ports, one of which is connected to the internal bus B1 of the communication control device 100 and the other of which is connected to the expansion bus B2 of the external computer 200, thereby controlling the communication. The access is made from both the built-in computer 11 of the apparatus 100 and the external computer 200.

The bidirectional access RAM 17 is alternately accessed by the built-in computer 11 and the external computer 200, and data written by one is read by the other, so that data can be transferred to each other. That is,
The bidirectional access RAM 17 functions as a kind of buffer that temporarily holds data transferred between the communication control device 100 and the external computer 200. This data transfer operation is started by an interrupt by the interrupt generation logics 15 and 16.

[0006]

However, the conventional communication control device described above has the following problems.

That is, in the above-described apparatus, in order to exchange commands / responses and transmission / reception data with the external computer 11, the memory (R) used by the built-in computer 11 of the communication control apparatus 100 for work.
AM13), a bidirectional access RAM 17 having two access ports is separately used. However, the bidirectional access RAM 17 is an element that requires a large chip area, and there is a problem that the use of this element inevitably increases the size and cost of the device configuration.

In the communication control device configured to support multi-line communication, data transfer between the built-in computer 11 and the external computer 200 is performed particularly efficiently in order to secure data transfer capability for each line. However, for this purpose, it is necessary to increase the storage capacity of the bidirectional access RAM 17 and reduce the number of times data is written and read alternately.

That is, the data write / read operation is started by an interrupt, but the operation start by this interrupt takes time. Therefore, in order to shorten the processing time, it is necessary to reduce the number of interrupts as much as possible. To this end, it is necessary to increase the amount of data that can be written / read by one interrupt, that is, to increase the bidirectional access RAM 1
7 needs to have a large storage capacity.

However, if the storage capacity of the bidirectional access RAM 17 is increased, the address space of the external computer 200 is occupied by the address space of the bidirectional access RAM 17, leaving no room for connecting other external devices. The problem arises.

According to the present invention, a communication control apparatus capable of transferring data with high efficiency to an external computer without occupying a large address space of the external computer with a relatively small and low-cost configuration. The purpose is to provide.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention operates autonomously by a built-in computer and connects a command / response with the external computer by connecting to a bus of the external computer. In a communication control device configured to transmit and receive data, the content is set via a bus on an external computer side, and the communication control device is installed so as to output the setting content to a bus on a built-in computer side. Address register, and a data register installed so as to be able to input and output from both the external computer bus and the built-in computer side bus. Stop the operation and clear the internal computer memory. Serial via the address register and the data register is obtained by configured to access from the outside.

With this, a communication control device having a relatively small-sized and low-cost configuration and capable of transferring data with high efficiency to and from an external computer without occupying a large address space on the external computer is provided. can get.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention operates autonomously by a built-in computer, and connects to a bus of an external computer to transmit / receive commands / responses to / from the external computer. A communication control device configured to transfer data, wherein the content is set via a bus on an external computer side, and the communication control device is set to output the setting content to a bus on a built-in computer side An address register, a data register installed so as to be able to input and output from both the external computer bus and the internal computer bus, and an operation of the internal computer in response to a command given via the external computer bus And stop the memory connected to the internal computer bus And an access control means for making an external access through the data register, thereby providing a relatively small-sized and low-cost configuration to the external computer side. A communication control device capable of transferring data with high efficiency to and from an external computer without occupying a large address space.

According to a second aspect of the present invention, in the first aspect, there is provided an address updating means for incrementing or decrementing the contents of the address register when accessing by the address register and the data register. As a result, the computer on the communication control device side is hardly burdened,
High-speed data transfer equivalent to DMA (Direct Memory Access) is possible.

According to a third aspect of the present invention, in the first or second aspect, the address register and the data register are provided separately for command / response and for transmission / reception data, respectively. As a result, the exchange of command / response and the exchange of transmission / reception data can be performed independently of each other, and the communication control device can be controlled by a command from an external computer even during communication.

According to a fourth aspect of the present invention, there is provided an address updating means for incrementing or decrementing the contents of the address register at the time of access by the address register and the data register, and a register for designating a range of the increment or decrement. This makes it possible to reliably prevent the contents of the RAM 13 in the communication control device 100 from being inadvertently destroyed.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 shows a first embodiment of the communication control device according to the present invention.

The communication control apparatus 100 shown in FIG. 1 includes a built-in computer 11 for centrally managing and controlling the operation in the apparatus, a ROM 12 storing an operation program of the computer 11, a work area, and a buffer area for various data. A RAM 13 to be provided, a functional device 14 for executing a communication process under the control of the built-in computer 11, an operation instruction register 18, an address register 19, a data register 20, an internal bus B1 for interconnecting the above-described units, etc. An external computer (a personal computer) that operates autonomously by the computer 11
By connecting to the expansion bus (ISA bus) B2 of the computer 200, commands / responses and transmission / reception data are exchanged with the external computer 200.

The address register 19 has its contents set via the bus B2 of the external computer 200 and is set so as to output the set contents, that is, the address, to the bus B1 of the built-in computer 11. I have.

The data register 20 has a bus B2 on the external computer 200 side and a bus B on the built-in computer 11 side.
1 so that input and output are possible from both sides.

The operation instruction register 18 outputs a control signal according to an instruction given from the external computer 200 via the bus B2, and thereby, the internal computer 11
Is stopped, and access control for externally accessing the RAM 13 connected to the bus B1 of the built-in computer 11 through the address register 19 and the data register 20 is realized. That is, the operation command register 18 constitutes a kind of access control means.

With the above configuration, for example, when the external computer (personal computer) 200 transfers a command or transmission data to the RAM 13 of the communication control device 100, the external computer 2OO sends the command or transmission data to the operation instruction register 18 via the bus B2. By sending a write operation instruction, sending an address to the address register 19, and writing data (command or transmission data) to the data register 20, the address register 19
The data of the data register 20 can be written to the address specified by. Thereby, the communication control device 1
The data can be written to a predetermined address of the RAM 13 by the same operation procedure as that for directly accessing the RAM 13.

When the external computer (personal computer) 200 receives a response or received data from the RAM 13 of the communication control device 100, it sends a read operation instruction to the operation instruction register 18 from the external computer 2OO via the bus B1. At the same time, by sending an address to the address register 19 and reading data (response or received data) from the data register 20, data can be read from the address specified by the address register 19. As a result, similar to the case of writing, the RA has the same operating procedure as that of directly accessing the RAM 13 of the communication control apparatus 100.
Data can be read from M13.

As described above, the bidirectional access RAM
Command / response and transmission / reception data between the external computer 200 and the communication control device 100 without depending on the communication control device 100. At this time, it should be noted that the data transfer is efficiently performed by the direct access operation to the registers 19 and 20 from both the communication control apparatus 100 and the external computer 200, and the external computer 200 is used for the access. The only address space seen from the side is the registers 18, 19 and 20.

With this configuration, highly efficient data transfer between the communication control device 100 and the external computer 200 can be performed with a relatively small-sized and low-cost configuration without occupying a large address space on the external computer 200 side. Can be done.

FIG. 2 shows a second embodiment of the communication control device according to the present invention. In the communication control device 100 shown in FIG. 2, an external computer (a personal computer) 200 is connected to the communication control device 100 via an address register 19 and a data register 20. When accessing the RAM 13, an address updating means 21 for incrementing or decrementing the contents of the address register 19 is provided.

Thus, access from the external computer 200 to the communication control apparatus 100 via the address register 19 and the data register 20 is performed while the address is automatically updated each time the access is performed. Therefore, when transferring a large amount of data, it is possible to access the address register 19 only at the start of the transfer, and to continuously transfer data only by accessing the data register 20 thereafter. As a result, the DMA (direct memory storage) is hardly applied to the computer 11 on the communication control apparatus 100 side.
Access) and high-speed data transfer equivalent to that of (access).

FIG. 3 shows a third embodiment of the communication control apparatus according to the present invention. In the communication control device 100 shown in FIG.
The address register and the data register are provided separately for command / response and for transmission / reception data (communication data). Specifically, as shown in the figure, an address register 22 and a data register 23 for exchanging a command and a response to the command, and an address register 24 and a data register 25 for exchanging transmission data and reception data are provided. Each is provided independently.

As described above, by dividing the registers 22 to 25 for command / response and transmission / reception data, it is possible to exchange command / response and transmission / reception data independently of each other. During communication, the communication control device 100 can be controlled by a command from the external computer 200.

FIG. 4 shows a fourth embodiment of the communication control apparatus according to the present invention. The communication control device 100 shown in FIG. 1 includes an address updating means 21 for incrementing or decrementing the contents of the address register 19 when accessing by the address register 19 and the data register 20.
And a register 26 for specifying the increment or decrement range.

This makes it possible to limit the access in the communication control device 100 from the external computer 200 via the address register 19 and the data register 20 to a certain address range. Inadvertent destruction of the contents can be reliably prevented.

[0033]

As described above, according to the present invention, with a relatively small-sized and low-cost configuration, high efficiency can be achieved between the external computer and the external computer without occupying a large address space. An advantageous effect that a communication control device capable of data transfer is obtained is obtained.

[Brief description of the drawings]

FIG. 1 shows a first example of a communication control device to which the technology of the present invention is applied.
Block diagram showing an embodiment of the present invention.

FIG. 2 shows a first example of a communication control device to which the technology of the present invention is applied.
Block diagram showing an embodiment of the present invention.

FIG. 3 shows a first example of a communication control device to which the technology of the present invention is applied.
Block diagram showing an embodiment of the present invention.

FIG. 4 shows a first example of a communication control device to which the technology of the present invention is applied.
Block diagram showing an embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration example of a conventional communication control device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 communication controller 11 built-in computer 12 ROM 13 RAM 14 functional device for executing communication processing 18 operation instruction register (access control means) 19 address register 20 data register B1 internal bus 21 address updating means 22 address register (command / response) 23 Data register (command / response) 24 Address register (transmitted / received data) 25 Data register (transmitted / received data) 26 Range designation register 200 External computer (personal computer) B2 Expansion bus (ISA bus)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-307718 (JP, A) JP-A-4-165505 (JP, A) JP-A-64-4158 (JP, A) (58) Field (Int. Cl. ⁷ , DB name) H04L 29/02 G06F 13/00 353

Claims (4)

(57) [Claims] A communication control device configured to operate autonomously by a built-in computer, and to transfer commands / responses and transmission / reception data to / from an external computer by connecting to a bus of the external computer. There is an address register set so that the contents are set via the bus of the external computer and output the setting contents to the bus of the built-in computer. A data register installed so that input and output can be performed from both sides of the bus, and the operation of the built-in computer is stopped according to a command given via the bus on the external computer side, and connected to the bus on the built-in computer side Memory is stored in the address register and data register A communication control device comprising: an access control unit configured to allow external access through the communication control unit. 2. The communication control device according to claim 1, further comprising address updating means for incrementing or decrementing the contents of the address register when accessing by the address register and the data register. 3. The communication control device according to claim 1, wherein the address register and the data register are provided separately for command / response and for transmission / reception data. 4. The apparatus according to claim 1, further comprising an address updating means for incrementing or decrementing the contents of said address register at the time of access by an address register and a data register, and a register for designating a range of said increment or decrement. 3. The communication control device according to any one of 3.