JPH0410836A - Communication controller - Google Patents

Abstract

PURPOSE:To quicken data transfer with a LAN by providing two LAN controllers for transmission and reception and exclusive transmission and reception buffer means to the communication controller respectively. CONSTITUTION:The communication controller is provided with two transmission and reception LAN controllers 15a, 15b and exclusive transmission and reception buffers 21a and 21b are provided between a local bus 12 and the two transmission and reception LAN controllers 15a, 15b. Thus, the read processing of a transmission data and the write processing of a received data by the transmission and reception LAN controllers 15a, 15b are executed directly to the buffers 21a, 21b without use of the local bus 12. Thus, the data management is simplified, the utilizing efficiency of the local bus is improved and the data transfer is quickened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a communication control device, and particularly to a communication control device having an interface with a LAN.

(Prior Art) Conventionally, a data processing device, a communication control board, etc. having an interface with a LAN is equipped with a communication control device 11 as shown in FIG. As shown in FIG. 3, the conventional communication control device 11 includes a local bus 12, a microprocessor 13, and a memory that stores data transferred via a LAN 18 and programs executed by the microprocessor 13. 14, a LAN controller 15, and a serial interface 1B.

When transmitting data from the communication control device 11 to the LAN 18, the transmission data stored in the memory 14 is sent to the LAN controller 1 via the local bus 12.
5, where it is converted into a LAN packet. This packet is converted into a transceiver interface signal by the serial interface 16 and then transmitted to the L A N 1g via the transceiver 17.

On the other hand, when the communication control device 11 receives data from the LAN 1B, the data on the LAN 18 is sent to the L A N 1B via the transceiver 17 and the serial interface 16.
The data is sent to the AN controller 15, where the data is converted and then stored in the memory 14 as received data.

In this way, in the conventional communication control device 11, transmission data and reception data are mixed in one memory 14, and it is necessary to manage these data by the microprocessor 13. For this reason, the microprocessor 13
This has the disadvantage that the data management process is complicated and the processing efficiency for data transfer is reduced.

Furthermore, the data management operation of the memory 14 by the microprocessor 13 is executed via the local bus 12;
Similarly, the LAN controller 13 also executes the process of reading out transmission data from the memory 14 and the process of writing received data into the memory 14 via the local bus 12. For this reason, the use of the local bus 12 by the LAN controller 13 is often limited by data management operations by the microprocessor 13, making it difficult to efficiently read out transmitted data and write received data. .

Furthermore, since one LAN controller 15 performs both transmission control and reception control, if a failure occurs in the LAN controller 15, the communication control device 11 and L
There was a drawback that all communication between AN18 was cut off.

(Problems to be Solved by the Invention) Conventionally, the processing efficiency of data transfer is reduced due to complicated data management by a microprocessor and data congestion on the local bus, and communication failures occur due to failure of the LAN controller. There were drawbacks.

The present invention has been made in view of the above points, and an object of the present invention is to provide a communication control device that can simplify data management by a microprocessor and improve the efficiency of use of a local bus, thereby realizing high-speed data transfer. Furthermore, it is an object of the present invention to provide a highly reliable communication control device that can avoid failures due to failure of a LAN controller.

[Structure of the Invention (Means and Effects for Solving the Problems)] A communication control device according to the present invention is provided with a transmitting LAN controller, a receiving LAN controller, and a transmitting LAN controller and a local bus. a transmission buffer means in which data is stored; a reception buffer means provided between the reception LAN controller and the local bus and in which reception data is stored; and a reception buffer means in which the reception data is stored;
interface means for controlling data transfer between each of the controller and reception LAN controller and the LAN; and data management means coupled to the transmission buffer and reception buffer via the local bus and for managing their respective data. The first feature is that

This communication control device is provided with two LAN controllers, one for transmission and one for reception, and furthermore, dedicated transmission buffer means and reception buffer means are provided between the local bus and the two LAN controllers, respectively. ing. Therefore, the LAN controller can directly execute the processing of reading transmission data and writing reception data to the buffer means without using the local bus. Therefore, data congestion on the local bus can be alleviated. Furthermore, since the transmitted data and received data are stored in separate buffers, data management processing by the data management means is also simplified. As a result, the LAN
It becomes possible to perform data transfer at high speed.

Further, the communication control device of the present invention includes first and second LAN controllers each having a transmitting and receiving function;
a first buffer means provided between the first LAN controller and the local bus; and a second buffer means provided between the second LAN controller and the local bus.
buffer means for controlling data transfer between each of the first and second LAN controllers and the LAN; in a first mode, the first and second LAN controllers act as transmitting and receiving controllers, respectively; a wiring connection between the first and second LAN controllers and the interface means, such that in a second mode, one of the first and second LAN controllers functions as a transmitting/receiving controller; A second feature is that the device includes a connection switching means for switching the data, and a data management means that is coupled to the first and second buffer means via the local bus and manages their respective data.

In this communication control device, the first and second LAN controllers can be used for transmission and reception, respectively, or only one can be used for both transmission and reception. Even if a failure occurs in the LAN controller, normal data transfer is possible.

Therefore, failures due to failure of the LAN controller can be avoided, and highly reliable communication can be achieved.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a communication control device 1 according to an embodiment of the present invention.
1' is shown. This communication control device 11' is similar to the conventional communication control device 11 shown in FIG.
This is for interfacing with the local bus 12, microprocessor 13, program memory 20, transmission buffer 21a1 reception buffer 21b1 transmission LAN controller 15a1 reception L
It includes an AN:I Citrol 15b, a gate circuit 22, and a serial interface 16.

The microprocessor 13 is connected to the local bus 12 and controls the entire communication control device 11', including data management processing for the transmission buffer 21a and the reception buffer 21b. This local bus 1
2 is further connected to a program memory 20, a transmission buffer 21a1, and a reception buffer 21b.

The program memory 20 stores various programs executed by the microprocessor 13.

The transmission buffer 21a is of a dual port type, and one port is connected to the local bus 12. This transmission buffer 21a is used to store transmission data to be transmitted to the LAN 18. Further, the reception buffer 21b is also of a dual port type, and one port is connected to the local /l//< bus 12. This reception buffer 21b is L A N 1
Used to store received data from 8. A transmitting LAN controller 15a and a receiving LAN controller +5b are connected to the other ports of the transmitting buffer 21a and the receiving buffer 21b, respectively.

The transmission LAN controller 15a has a transmission buffer 2.
Transmission data is read from 1a, converted to packet type data for LAN, and output.

The receiving LAN controller 15b extracts text data from the received packet type data and writes it into the receiving buffer 21bl. Each of the transmitting LAN controller 15a and the receiving LAN controller 15b originally has both transmitting and receiving control functions, but depending on the mode setting, only one of the transmitting and receiving functions can be activated. In this embodiment, as described above, only the transmitting function of the transmitting LAN controller 15a and the receiving function of the receiving LAN controller 15b are used.

The gate circuit 22 selects the output of either the transmitting LAN controller 15a or the receiving LAN controller 15b and transfers it to the serial interface 16, and also prevents the own station from receiving packets transmitted by the own station. It has the function of blocking the received signal. The gate circuit 22 also includes a serial interface 16.
The output from is supplied to both the transmitting LAN controller 15a and the receiving LAN controller 15b.

The serial interface 16 transmits the output of the transmission LAN controller 15a, that is, the transmission data, to the transceiver 1.
7 to LAN 1g, and also transmits received data from LAN 1& received via transceiver 17 to reception controller 15b.

FIG. 2 shows an example of wiring connections realized by the gate circuit 22.

In FIG. 2, TXC is a transmission clock, TXD is transmission data, RTS is a transmission request signal, CTS is a transmission permission signal, RXC is a reception clock, RXD is reception data,
CR5 is a reception indication signal, and CDT is a collision indication signal.

Further, 31 and 32 are selectors, and the selector 31 selects either one of the transmission data TXD of the transmission LAN controller 15a and the transmission data TXD of the reception LAN controller 15b.
Transmission data TXD of controller i5a is selected)
, it is serial interface] 6 transmission data T
Supplied to the XD terminal. The selector 32 selects the transmission request signal RTS of the transmission LAN controller 15a and the reception LAN
In this embodiment, the transmission request signal RTS of the transmitting LAN controller 15b is selected), and the transmission request signal RT of the serial interface 16 is selected.
Supplied to S terminal.

Further, 33 and 34 indicate connection cutoff nodes.

The node 33 connecting the transmitting LAN controller 15a and each reception display signal CR5 terminal of the serial interface 16 is cut off when the transmitting request signal RTS is generated from the receiving LAN controller 15b. Also,
The node 34 connecting the reception LAN controller 15b and each reception display signal CR8 terminal of the serial interface 16 is cut off when the transmission request signal RTS is generated from the transmission LAN controller 15a.

When the two LAN controllers 15a, 15b and the serial interface 16 are connected by wiring in this way, the transmission data TXD and the transmission request signal RTS selected by the selectors 31 and 32, respectively, are input to the serial interface 16, and the serial interface 16 A packet is transmitted from the transceiver 19 to the transceiver 19. At this time, the packet is echoed back from the transceiver 19, but since the input node of the reception indication signal CR5 of the LAN controller on the non-sending side is cut off, the reception indication signal CR3 is transmitted only to the LAN controller on the transmission side. As a result, the LAN controller on the sending side can determine that the packet has been correctly transmitted, and can normally complete the transmission.

On the other hand, signals related to reception are sent from the serial interface 1B to the two LAN controllers 15a.

15b. The reception display signal CR3 is also transmitted to both of the two LAN controllers 15a and I5b unless a transmission request is output.

Therefore, if the reception LAN controller 15b is set to reception mode, the reception LAN controller 15b
can receive packets from serial interface 16.

Therefore, two LAN controllers 15a.

When one of the LAN controllers 15b fails, the selector 31 selects the transmission data TXD and the transmission request signal RTS from the normal LAN controller.
．． 32 and set the normal LAN controller to receive mode, one LAN
The controller can also perform both transmission and reception.

In the communication control device 11' configured in this way,
Two LAN controllers 15a for transmission and reception,
Furthermore, a dedicated transmitting buffer 21a and a dedicated receiving buffer 21-b are provided between the local bus 12 and two LAN controllers 15a and 15b, respectively. Therefore, the processing of reading transmission data and writing reception data by the LAN controllers 15a and 15b is performed using the local bus 12.
It can be executed directly on the buffers 21a and 21b without using . Therefore, local bus 1
Data congestion on 2 can be alleviated. Furthermore, since the transmission data and reception data are stored separately in the two buffers 21a and 21b, data management processing by the microprocessor 13 is also simplified. As a result, LA
It becomes possible to perform data transfer with N 12 at high speed.

In addition, the two LAN controllers 15a can be connected by changing the mode and setting the selectors 31 and 32.

15b can be used for transmission and reception, and either of the two LAN controllers 15a and 15b can be used for both transmission and reception, so even if one LAN controller fails, Normal data transfer is possible. Therefore, failures due to failure of the LAN controller can be avoided, and highly reliable communication can be achieved.

[Effects of the Invention] As described above, according to the present invention, data management by a microprocessor can be simplified, local bus usage efficiency can be improved, and data transfer can be made faster. Furthermore, by duplicating the LAN controller, a highly reliable communication control device can be realized.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a communication control device according to an embodiment of the present invention, and FIG. 2 shows a wiring connection state realized by a gate circuit provided in the communication control device shown in FIG. 3 are block diagrams showing a conventional communication control device. 12...Local bus, 13...Microprocessor, 15a...Transmission LAN controller, 15b.
... LAN controller for reception, 16... serial interface, 17... transceiver, 21a...
- Transmission buffer, 21b...reception buffer. Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (2)

[Claims] (1) A transmitting LAN controller and a receiving LAN controller, a transmitting buffer means provided between the transmitting LAN controller and the local bus and storing transmitted data, and a transmitting LAN controller and a receiving LAN controller, a reception buffer means provided between the transmitting LAN controller and the receiving LAN controller to store the received data; an interface means controlling data transfer between the transmitting LAN controller and the receiving LAN controller and the LAN; 1. A communication control device comprising a data management means coupled to a trust buffer and a reception buffer and managing each data thereof. (2) first and second LAN controllers each having a transmitting and receiving function; a first buffer means provided between the first LAN controller and the local bus; and the second LAN controller. a second buffer means provided between the controller and the local bus; an interface means for controlling data transfer between each of the first and second LAN controllers and the LAN; The first and second LAN controllers function as transmitting and receiving controllers, respectively, and in the second mode, one of the first and second LAN controllers functions as a transmitting and receiving controller. connection switching means for switching wiring connections between the LAN controller and the interface means; and data management means coupled to the first and second buffer means via the local bus and managing their respective data. A communication control device comprising: