JPH10254800A - Serial interface transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a transfer speed with a small transmitting buffer by adding received transfer data to an in-use frame and returning them when a data reception side returns the in-use frame. SOLUTION: An input/output processor 3 and an input/output device 4 are connected by a serial interface and by an instruction from a central processor 1, data are transferred between the input/output processor 3 and input/output device 2. When the transfer data are sent to the serial interface, they are converged into frame format and sent, and when the transfer data are received, the transfer data are extracted from a received frame and processed as specified. Here, when the data reception side returns the in-use frame for some reason, the received transfer data are added to the in-use frame and returned. Consequently, the data transmission side need not hold data frame information sent to its transmitting buffer before for the retransmission of the data frame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a serial interface transfer device for connecting an input / output processing device and an input / output device with a serial interface.

[0002]

2. Description of the Related Art A conventional serial interface transfer device has a central processing unit 1, a main storage device 2, an input / output processing device 3, and an input / output device 4, as shown in FIG. The input / output processing device 3 and the input / output device 4 are connected by a serial interface.

When data is transferred between the input / output processing device 3 and the input / output device 4, first and second frame transmitting means 30 and 40 for converting into a format called a frame and transmission frame information are held. First and second transmission buffers 31 and 41 for storing received frames, first and second reception buffers 33 and 43 for storing received frames, and first and second frame identification means 32 for analyzing received frames. 42 is provided for each of the input / output processing device 3 and the input / output device 4. The input / output device 4 has a built-in auxiliary storage device 45.

When the input / output processing device 3 transfers data from the main storage device 2 to the input / output device 4 according to an instruction from the central processing unit 1, the transferred data is called a frame shown in FIG. The data is converted into a format and transmitted to the serial interface via the first transmission buffer 31.

The input / output device 4 having received the data frame stores the data frame information in the second reception buffer 43, and recognizes the data frame as a data frame by the second frame identification means 42. If the input / output device 4 can process the received data frame, the input / output device 4 instructs the second frame transmitting means 40 to return the response frame (see FIG. 6) to the input / output processing device 3, and executes the data frame reception process. Do.

However, if processing cannot be performed for some reason, the second frame transmitting means 40 is instructed to return the in-use frame (see FIG. 6) to the input / output processing device 3, and the data frame is transmitted. Discard.

When the response frame is returned from the input / output device 4, the input / output processing device 3
If it is determined that the data frame has been transmitted previously, it is considered that the data frame has been processed by the input / output device 4, and the information in the first transmission buffer 31 holding the data frame is discarded. However, if it is determined that the in-use frame has been returned, the previously transmitted data frame is not processed by the input / output device 4 and the data frame held in the first transmission buffer 31 is re-read. The first frame transmitting means 30 is instructed to transmit.

[0008]

In the prior art,
The first and second transmission buffers 31, 41 after transmitting the data frame until the corresponding response frame is returned.
Cannot discard the data frame information inside. This is because when the used frame is returned, the same data frame needs to be transmitted again.

When the distance between the input / output processing device 3 and the input / output device 4 is long, the time from the transmission of the data frame to the return of the corresponding response frame becomes long. First and second transmission buffers 31 and 41
Since the data frame information cannot be discarded, data frames cannot be transmitted continuously, and the transfer speed is reduced.

This problem can be solved by preparing a plurality of transmission buffers and adopting a configuration capable of holding a plurality of data frames. However, this causes a problem that the amount of heart wear increases.

It is therefore an object of the present invention to provide a serial interface transfer device capable of improving the transfer speed with a small transmission buffer (amount of hardware).

[0012]

According to the present invention, a central processing unit, a main storage, an input / output processing unit connected to the central processing unit and the main storage, and a connection to the input / output processing unit are provided. A serial interface transfer device in which the input / output processing device and the input / output device are connected by a serial interface, wherein the input / output device and the input / output device are connected by an instruction from the central processing unit. Data is transferred to and from the input / output device, when transmitting the transfer data to the serial interface, the data is converted into a frame format and transmitted, and when the transfer data is received, the transfer data is extracted from the received frame received. Performs predetermined processing. If the received frame cannot be processed for any reason, the used frame is returned to the transmitting side, and the data receiving side A function of storing the transfer data received in the in-use frame to be returned when the received frame cannot be processed and returning it to the data transmitting side, and a function of transmitting the data stored in the in-use frame upon receiving the in-use frame And a function of retransmitting a frame using data.

Further, according to the present invention, a central processing unit;
A serial interface transfer device having a main storage device, an input / output processing device, and an input / output device, wherein the input / output processing device and the input / output device are connected by a serial interface; A first frame transmission unit for converting transfer data into a frame format for transmission on the serial interface; a first transmission buffer for holding a frame to be transmitted; and a first reception buffer for holding a reception frame First frame identification means for judging the type of the received frame and performing processing in accordance with the type, and first frame transfer means for transferring transfer data contained in the received frame to the first transmission buffer The input / output device has an auxiliary storage device for performing data transfer with the input / output processing device, and the same as the input / output processing device. Serial interface transfer device, comprising: a second frame transmission means having a function, a second transmission buffer, a second frame identification means, a second reception buffer, and a second frame transfer means. Is obtained.

Further, according to the present invention, the input / output processing device performs data transfer between the main storage device and the input / output device independently of the central processing device according to an instruction from the central processing device. A serial interface transfer device characterized by performing control is obtained.

[0015]

The serial interface transfer device according to the present invention comprises:
A device that connects the I / O processing device and the I / O device with a serial interface and transfers data between the I / O processing device and the I / O device according to instructions from the central processing unit. Is transmitted after being converted into a format generally called a frame when transmitting, and when receiving transfer data, transfer data is extracted from the received frame and a predetermined process is performed. At this time, if the received frame cannot be processed for some reason, the used frame is returned to the transmitting side.

A function of storing the received transfer data in the in-use frame returned when the data receiving side cannot process the received frame for some reason and returning the data to the data transmitting side; and a function of the data transmitting side receiving the in-use frame. Has a function of retransmitting the frame using the transfer data stored in the used frame.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of a serial interface transfer apparatus according to the present invention will be described with reference to a block diagram of FIG.

Referring to FIG. 1, a serial interface transfer device includes a central processing unit (hereinafter referred to as a CPU) 1
And a main storage device (hereinafter, referred to as MEM) 2, an input / output processing device (hereinafter, referred to as IOP) 3, and an input / output device (hereinafter, referred to as I / O) 4.

The IOP 3 is controlled by the CPU 1 according to an instruction from the CPU 1.
1 is a device for controlling data transfer between the MEM 2 and the I / O 4 independently of each other. IOP3 and I / O4 are connected by a serial interface. I / O
4, a general auxiliary storage device 45 such as a magnetic disk or a magnetic tape is built in, and data is transferred between the IOP 3 and the auxiliary storage device 45.

Inside the IOP 3, a first frame transmitting means 30 for converting transfer data into a frame format as shown in FIG. 2 for transmission on a serial interface.
And a first transmission buffer 3 for holding a frame to be transmitted.
1 and a first reception buffer 33 for holding a reception frame.
A first frame identification unit 32 that determines the type of the received frame and performs processing according to the type, and a first frame transfer unit that transfers the transfer data included in the received frame to the first transmission buffer 31 34.

Inside the I / O 4, the second frame transmitting means 40, the second transmitting buffer 41, the second frame identifying means 42, the second receiving buffer 43, and the second It has a frame transfer means 44 and the auxiliary storage device 45 described above.

Now, consider a case where data in MEM 2 is transferred to I / O 4 in accordance with an instruction from CPU 1. FIG. 3 is a flowchart of a data frame transmission procedure of the serial interface transfer device. The data frame transmission procedure will be described below with reference to FIGS.

The IOP 3 receiving the data transfer instruction (step S 1) from the CPU 1 reads necessary transfer data from the MEM 2, and transfers the SOF (information indicating the start of a frame), Type (indicating a data frame here), EOF
It is converted into a frame format to which (information indicating the end of the frame) is added (step S2). The converted frame information is held in the first transmission buffer 31 (step S3).
), And sequentially transmitted on the serial interface (step S4). When all the frame information has been transmitted on the serial interface, the frame information is no longer needed, so the frame information in the first transmission buffer 31 is discarded (step S5). If there is transfer data to be transferred, this is repeated.

FIG. 4 is a flowchart showing a frame receiving procedure of the serial interface transfer device. The frame reception procedure will be described with reference to FIGS.

Via the serial interface, IOP
The I / O 4 that has received the data frame from No. 3 stores the data frame in the second reception buffer 43 (step S1).
1), the frame received by the second frame identification means 42 is recognized as a data frame (step S1).
2).

If the data frame can be processed inside the I / O 4, the second frame transmitting means 40 is instructed to return a response frame (a frame indicating that the data frame has been processed) (step S16). ), And performs processing such as storing the received transfer data in the auxiliary storage device 45 (steps S17 and S18).

However, if the data frame received by the I / O 4 cannot be processed for some reason, the frame transmitting means 40 is instructed to use the frame in use as shown in FIG. (Step S13). At this time, the transfer data in the reception buffer 43 is transferred to the transmission buffer 41 in order to be added to the in-use frame by the frame transfer means 44 which is a feature of the present invention (step S14). Thereafter, the in-use frame is returned to the IOP3 via the serial interface (step S15).

IO receiving a busy frame from I / O4
P3 stores the used frame in the reception buffer 33, and recognizes that the used frame has been returned by the frame identifying means 32. When the used frame is returned, it means that the previous data frame has not been processed by the I / O 4 side.
Instruct to retransmit the data frame (step S1)
9) The transfer data to be retransmitted by the frame transfer means 34 is transferred from the reception buffer 33 to the transmission buffer 31 (step S20). Thereafter, the data frame is retransmitted to the I / O 4 via the serial interface (step S21).

When a data frame is transmitted from the I / O 4 to the IOP 3, the same operation as above is performed, except that the operations of both are switched.

[0030]

According to the serial interface transfer device of the present invention, when the data receiving side returns the busy frame for some reason, the data transfer side adds the received transfer data to the busy frame and returns it, thereby enabling the data transmitting side to return. It is no longer necessary to retain the previously transmitted data frame information in its own transmission buffer to retransmit the data frame when the used frame is returned, and retransmit the data frame using the transfer data included in the used frame. I just need. Therefore, a small transmission buffer (hardware amount)
Can improve the transfer speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a serial interface transfer device according to the present invention.

FIG. 2 is a frame configuration diagram of the serial interface transfer device shown in FIG. 1 of the present invention.

FIG. 3 is a flowchart of a data frame transmission procedure of the serial interface transfer device shown in FIG. 1;

FIG. 4 is a flowchart of a frame receiving procedure of the serial interface transfer device shown in FIG. 1;

FIG. 5 is a block diagram showing a conventional serial interface transfer device.

6 is a frame configuration diagram of the serial interface transfer device shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Central processing unit (CPU) 2 Main storage unit (MEM) 3 Input / output processing unit (IOP) 4 I / O 30 First frame transmission unit 31 First transmission buffer 32 First frame identification unit 33 First Receive buffer 34 First frame transfer means 40 Second frame transmission means 41 Second transmission buffer 42 Second frame identification means 43 Second reception buffer 44 Second frame transfer means 45 Auxiliary storage device

Claims (3)

[Claims] A central processing unit, a main storage device, an input / output processing device connected to the central processing device and the main storage device, and an input / output device connected to the input / output processing device;
A serial interface transfer device in which the input / output processing device and the input / output device are connected by a serial interface, wherein data is transmitted between the input / output processing device and the input / output device according to an instruction from the central processing unit. When transmitting the transfer data to the serial interface, the data is converted into a frame format and transmitted.When the transfer data is received, the transfer data is extracted from the received frame and subjected to predetermined processing. When the received frame cannot be processed, the used frame is returned to the transmitting side, and when the data receiving side cannot process the received frame for any reason, the received transfer data is stored in the used frame to be returned to the data transmitting side. The function to return and the data transmitting side that received the in-use frame stores it in the in-use frame And a function of retransmitting a frame using the transferred data. 2. An apparatus comprising a central processing unit, a main storage device, an input / output processing device, and an input / output device, wherein the input / output processing device and the input / output device are connected by a serial interface. A serial interface transfer device, wherein the input / output processing device converts a transfer data into a frame format for transmission on the serial interface, a first frame transmission unit, a first transmission buffer for holding a frame to be transmitted, A first reception buffer for holding a reception frame, first frame identification means for determining a type of the reception frame and performing a process according to the type, and transmitting the transfer data contained in the reception frame to the first transmission buffer First frame transfer means for transferring data to a buffer, wherein the input / output device performs auxiliary data transfer with the input / output processing device The second frame transmitting means having the same function as the input-output processor, the second transmission buffer,
A serial interface transfer device, comprising: a second frame identification unit, a second reception buffer, and a second frame transfer unit. 3. The serial interface transfer device according to claim 1, wherein said input / output processing device is independent of said central processing unit by an instruction of said central processing device, and said main storage device and said input / output device are connected to each other. A serial interface transfer device for controlling data transfer between the serial interface and the serial interface.