JPH0746332B2 - Signal converter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a signal converter provided between a channel device and an input / output control device of an information processing system.

A channel device is generally provided as a mechanism for mediating transfer of control information and data between a so-called input / output device and a central processing unit and a seed storage device of an information processing system. Control the input / output device.

As a transfer control method of information exchanged between the channel device and the input / output control device, one standard method is usually defined.
In principle, it does not depend on the type of input / output device.

However, if the information processing system model is different,
In general, the transfer control method is different, and it is not possible to directly connect the channel device and the input / output control device of a different model. Therefore, when a connection of such a combination is required, the signal and control method are converted in the middle. It is necessary to put the device to do.

[Problems to be solved by conventional technology and invention]

As an interface method between a channel device (hereinafter referred to as CHP) and an input / output control device (hereinafter referred to as IOC), there are two methods used when relatively high speed data transfer is required.

In the first method, as shown in FIG. 2 (a), from CHP1
For data transfer to IOC2, a data line 3 for transferring 2-byte data in bit parallel and control lines 4 and 5 are provided.

In this method, as shown in Fig. 2 (b), IOC2
Requests data by turning on the control line 5 for each data transfer.

When the CHP1 receives the signal on the control line 5, it sends the transfer data (2 bytes) to the data line 3, and then turns on the control line 4.

The IOC2 receives the data on the data line 3 and holds it in an appropriate register while the control line 4 is on, and then the control line 5
Turn off.

The CHP1 turns off the control line 4 by turning off the control line 5.

By the above, data transfer of 1 time (2 bytes) is completed,
By repeating this operation, data of a required length is transferred.

In the second method, as shown in FIG.
A data line 7 and control lines 8 and 9 for transferring byte data in bit parallel are provided between CHP11 and IOC12.

In data transfer, the IOC 12 issues a data transfer request by sending an ON signal of a fixed length to the control line 9.

Each time CHP11 detects that control line 9 is on, data line 7
To the control line 8 and the IOC 12 receives the information of the data line 7 while the control line 8 is on as data, and repeats the above operation. Transfer data.

In order to achieve high-speed data transfer, the IOC 12 sends a data transfer request signal on the control line 9 after starting the data transfer process.
The signal is sent at a fixed cycle (for example, 2 MHz) independently of the signal from the other party, and when the operation proceeds normally, CHP11 sends the data in synchronization with the data transfer request.

The first method requires transmission / reception of a control signal between the transmission / reception devices for each transfer, whereas the second method does not require such a round trip of the control signal for each transfer. Even if the parallel transfer data width of the line is small, it is possible to obtain the data transfer rate equivalent to that of the first method.

When connecting the CHP1 of the first method and the IOC12 of the second method as described above, for example, as shown in FIG. 4, a signal converter 20 is provided between the two, and the CHP1 and the signal converter are connected. 20 is connected to the 2-byte data line 23 of the first system and the control lines 24 and 25.

Further, the signal conversion device 20 and the IOC 12 are the same as those of the second system.
Connected by byte data line 27 and control lines 28 and 29.

The data transfer request signal from the IOC12 is sent to the control line 29 as described above.
When it is periodically issued (corresponding to the control line 9), the signal converter 20 relays this data transfer request signal to the control line 25 in the control unit 30 as a data transfer request signal of the first method.

However, as is apparent from the above description, according to the first method, the timing of dropping the signal of the control line 25 needs to be converted so as to be controlled by the signal of the control line 24.

Since the data is sent out to the data line 23 by 2 bytes in the same manner as described above, the signal conversion device 20 receives the data while the control line 24 is on and holds it in the buffer 31.

The signal conversion device 20 sends the data of the buffer 31 to the data line 27 byte by byte and transfers it to the IOC 12, and this transfer is synchronized with the data transfer request signal of the control line 29 according to the second method. Further, in parallel with this data transfer, the same signal as in the case of the control line 8 is sent to the control line 28.

As is well known, the data transfer is started after the command transfer from the CHP to the IOC and the response of the status information from the IOC to the command transfer.

That is, the command for designating the input / output operation from the CHP 1 to the IOC 12 is transferred via the data lines 23 and 27, for example, in substantially the same manner as the data transfer of the first method.

When the command transfer is completed, the CHP 1 then sends a signal requesting the transfer of the status information to the IOC 12 by turning on the control line 32.

In response to this, when the status information from the IOC 12 is transferred via the data line 33, the CHP 1 turns off the status information transfer request on the control line 32.

At this time, IOC12 is ready to execute commands,
If the specified command specifies data writing, the IOC 12 may immediately start the data transfer request with the control line 32 being turned off as a control factor for the status information transfer.

Here, in the first method, the progress of data transfer can be controlled at any time by delaying the time when CHP1 turns on control line 4 in response to a data request from control line 5 of IOC2. In the second method, as described above, after the data transfer request is started, the data receiving side continues to repeat the request independently.

Therefore, the CHP11 of the second method needs a function of controlling the transmission start timing of the data transfer request from the IOC12 according to the progress status of the control in the CHP11. Therefore, it is not necessary in the first method CHP1.

Therefore, when the IOC 12 of the second method is connected to the CHP 1 of the first method by simply inserting the signal conversion function, there is a problem that so-called overrun may occur.

[Means for solving problems]

The above-mentioned problem is that the control method of signal transmission / reception for data transfer control between the channel device and the input / output control device of the information processing system is Regarding the data transfer request signal for requesting the data transfer, in the first method, in response to the data transfer request signal, a response for controlling the end of the data transfer request signal from the channel device and the sending of the next data transfer request signal. In the second method, the data transfer request signal of a predetermined length is transmitted at a predetermined interval regardless of the response from the channel device. In order to transfer data between the channel device that controls the first method and the input / output control device that controls the second method, a connection is made between the channel device and the input / output control device. hand A device for relaying a signal and transfer data transmitted and received between the both devices, wherein a buffer for relaying the transfer data, the response signal and the data transfer request signal are converted based on the first and second systems. And a signal sent from the channel device so as to enable the first transmission start of the data transfer request signal to the input / output control device, This is solved by the signal conversion device of the present invention having a delay control unit that delays for a predetermined time and relays to the input / output control device.

[Action]

That is, the signal converter provided between the CHP of the first method and the IOC of the second method extends the IOC of the status information transfer request signal from the CHP for a certain period of time until the signal is converted to the IOC.
Try to relay to.

This extension time is the time required before CHP can start data transfer.

By doing so, even if the IOC immediately transmits the data transfer request signal to start the transfer operation when the status information transfer request signal is turned off, the transfer can be continued without causing overrun.

〔Example〕

FIG. 1A is a block diagram showing the configuration of an embodiment of the present invention. In the figure, the same parts as those in FIG. 4 are designated by the same reference numerals.

The signal conversion device 40 of the present invention is a control line for a status information transfer request.
32 is relayed to the IOC 12 via the delay control unit 41.

As shown in FIG. 1B, the delay control section 41 immediately relays the ON signal of the control line 32 to the IOC 12 as the ON signal of the control line 42, and when the signal of the control line 32 changes from ON to OFF. ,
A certain extension time is provided to extend the ON signal of the control line 42 and delay the time to turn it off.

The IOC 12 sends state information to the data line 33 by detecting the ON signal of the control line 42 as in the conventional case, and the CHP 1 turns off the control line 32 by receiving the state information. Since the signal on the control line 42 is still in the ON state as shown in b), the progress of control in the IOC 12 is delayed, and the data transfer request signal to the control line 29 is delayed by that amount as shown in the figure.

Therefore, the extension time of the ON signal of the control line 42 is equal to or longer than the time required for the CHP1 to turn off the control line 32 and then read the first data from the main storage device and become ready for data transmission. By setting to, it is possible to prevent the occurrence of overrun as described above.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, it is possible to connect the input / output control devices of different transfer control methods to the channel device of the information processing system without causing overrun of data transfer. , There is a remarkable industrial effect of increasing the flexibility of the system configuration.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration or the like of an embodiment of the present invention, FIG. 2 is a diagram showing a configuration or the like of a first transfer control system, FIG. 3 is a diagram showing a configuration or the like of a second transfer control system, FIG. 4 is a diagram showing a configuration example of a conventional signal conversion device. In the figure, 1 and 11 are CHP, 2 and 12 are IOC, 3, 7, 23 and 27 are data lines, 4, 5, 8, 9, 24, 25, 28 and 29 are control lines, and 24 and 40 are signals. A converter, 30 is a control unit, 31 is a buffer, 32 and 42 are control lines, 33 is a data line, and 41 is a delay control unit.

Claims (1)

[Claims] 1. There are two control methods for transmitting and receiving a signal for controlling data transfer between a channel device and an input / output control device of an information processing system, and there is one control system from the input / output control device to the channel device. Regarding the data transfer request signal for requesting data transfer every time, in the first control method, in response to the data transfer request signal, the channel device ends the data transfer request signal and sends the next data transfer request signal. Is configured to be transmitted at a predetermined interval regardless of the response from the channel device, and the second control method is configured to transmit the data transfer request signal having a predetermined length. In this case, in order to transfer data between the channel device that controls the first control method and the input / output control device that controls the second control method, the channel device and A signal conversion device connected to an output control device for relaying signals and transfer data transmitted and received between the two devices, a buffer for relaying the transfer data, the response signal and the data transfer request signal. And a control unit that performs conversion based on the first and second control methods and relays the data, and the channel device that enables the first transmission of the data transfer request signal to the input / output control device. And a delay control unit for delaying a signal transmitted from the channel device by a predetermined time after receiving the signal from the channel device and relaying the signal to the input / output control device.