JPH04344552A - Multi-input/output control method - Google Patents

Abstract

PURPOSE:To realize high speed switching of multi-input/output control. CONSTITUTION:FIFO(first-in first-out) memory 5 sequentially stores both numbers of input/output devices 11-14 whose initiation are required by a master unit and number of input/output devices to which control is switched for multicontrol. Microprocessor 4 starts an input/output device whose number is read out of the FIFO memory 5, and controls the input/output device by using control information read out of a control information area corresponding to local memory 2. When the control comes to the end, if the FIFO memory 5 is not empty, number of input/output devices under the control and the control information are stored in the FIFO memory 5 and local memory 2, the next number is read out of the FIFO memory 5 to switch the control.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple input/output control system in which an input/output control device including a microprocessor controls a plurality of input/output devices.

0002

[Prior Art] Conventionally, this type of multiple input/output control method
It has a storage means for saving the register of the processor of the input/output control device and storing the control information of each input/output device, and this storage means is divided into the control information area of each input/output device, and each input/output Number the devices, and store the number of the input/output device indicating the next control in each divided control information area, and the number of the input/output device currently being controlled is the last one of the activated input/output devices. Multiple input/output control was switched by storing the information in the control information area of the input/output device.

0003

[Problems to be Solved by the Invention] In the conventional multiple input/output control method described above, as the degree of multiplicity increases when switching control of each input/output device, the number of the input/output device to be controlled last is detected and the number of the current input/output device is detected. The disadvantage is that it takes time to store the number of the input/output device being executed.

0004

[Means for Solving the Problems] The multiple input/output control method of the present invention includes a plurality of input/output devices each having a number,
A first storage device that stores, in a first-in, first-out manner, the number of the input/output device for which the host device has requested activation and the number of the input/output device whose control is to be switched to the next input/output device for multiplex control.
a second storage means capable of storing control information for each of the input/output devices; and a second storage means connected to the plurality of input/output devices via an external bus, and an internal The input/output device connected via a bus and having the number read from the first storage means is activated and controlled using the control information read from the second storage means. If the means is empty, a microprocessor stores the number and control information of the input/output device being controlled in the first and second storage means and then reads out the first storage means to switch control; It is equipped with

Further, the multiple input/output control system of the present invention has a configuration in which a signal line for transmitting to the microprocessor whether or not the first storage means is empty is provided independently of the internal bus. You can.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

[0008] The input/output control device 1 controls the input/output devices 11, 12, 13, and 14 connected to the external bus 6 in response to an activation request from a central processing unit, which is a host device. The input/output control device 1 includes a microprocessor 4 and control information areas 21, 22, 23 of the input/output devices 11, 12, 13, 14.
, 24, an event at the time of a startup request to the input/output devices 11, 12, 13, 14 of the central processing unit, and the input/output devices 11, 12, 13, 14.
There is a FIFO memory 5 that can store events in the order in which they occur and read them out in the order in which they occur when multiplex control is switched, and the FIFO memory 5 is set to "1" when the above-mentioned event does not occur and the FIFO memory 5 is empty, and when it is not empty. A signal transmission line 7 that transmits “0” to the microprocessor 4, a local memory 2, and an FI
It is composed of an FO memory 5 and an internal bus 3 that connects the microprocessor 4.

Next, the multiplex control operation performed by the input/output control device 1 will be explained.

Control numbers are assigned to the input/output devices 11, 12, 13, and 14, respectively, as "01", "02", "03", and "04".
”. When receiving a startup request from the central processing unit to the input/output device 11 via the external bus 6, the microprocessor 4 stores the control number “01” of the input/output device 11 in the FIFO memory 5. When the input/output device 12 receives a startup request from the processing device, the input/output device 11
The microprocessor 4 accepts the startup request before going to start up the FIFO.
The control number "02" of the input/output device 12 is stored in the memory 5. Similarly, if the central processing unit subsequently issues a startup request to another input/output device, the control number of that input/output device is stored in the FIFO memory 5.

Next, if no activation request is received from the central processing unit, the FIFO memory 5 is read. The control number "01" for which the startup request was first received is first read out, and the startup process of the input/output device 11 is started, and when the processing ends, the control is switched. To switch the control, first
It is determined whether the IFO memory 5 is empty or not based on the state of the signal transmission line 7, and when it is "1" indicating that it is empty, the control continues without changing the control, and "0" indicating that it is not empty.
In this case, store the control number “01” in the FIFO memory 5,
Information necessary for control is stored in the control information area 21 of the input/output device 11 of the local memory 2, and the FIFO memory 5 is read out. If the read control number is "02", information necessary for control is read from the control information area 22 of the input/output device 12 in the local memory 2 and control of the input/output device 12 is started. Multiple input/output control is realized by repeating the above operations.

0012

As explained above, the present invention stores the number of the input/output device for which activation is requested or the input/output device whose control is to be switched to another input/output device in the first storage means on a first-in, first-out basis. Therefore, there is an effect that switching of multiple input/output control can be performed faster. In particular, greater effects can be obtained when the degree of multiplicity is high.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

[Explanation of symbols]

1 Input/output control device 2. Local memory 3 Internal bus 4. Microprocessor 5 FIFO memory 6 External bus 7 Signal transmission line 11-14 Input/output device

Claims (2)

[Claims] Claim 1: A plurality of input/output devices each numbered, the number of the input/output device requested to be activated by a host device, and the input/output device whose control is switched to the next input/output device for multiple control. a first storage means for storing control information for each of the input/output devices on a first-in, first-out basis; a second storage means for storing control information for each of the input/output devices; The input/output device connected to the first and second storage means via an internal bus and having the number read from the first storage means is activated and controlled using the control information read from the second storage means. If the first storage means is not empty at a break in control, the number and control information of the input/output device being controlled are stored in the first and second storage means, and then the first storage means is read out. A multiple input/output control method characterized by comprising a microprocessor that switches control. 2. The multiple input/output device according to claim 1, wherein a signal line for transmitting to the microprocessor whether or not the first storage means is empty is provided independently of the internal bus. control method.