SU690471A1 - Peripheral devices-electronic computer interface - Google Patents

Description

(54) DEVICE FOR CONNECTING PERIPHERAL DEVICES WITH COMPUTERS The aim of the invention is to enhance the functionality of the device. This goal is achieved by introducing two switching units and a transmission control unit into the device, the first input and output of which are respectively the control input and output of the device, the second input and output of the transmission control unit are respectively connected to the second and third inputs of the status register unit and control, and the third output - to the control input of the second switching unit, the group of inputs of which is connected to the group of outputs of the block of input registers and the group of inputs of the first switching unit, and groups outputs - to the group of input registers of terminal block input of the second switching unit is connected to the second output of the receiver unit of the third switching unit output is connected to the second input unit transmitter, and inputs - vyhodambloka to respective interrupts. The drawing shows the block diagram of the device for p input and m output peripheral devices. 1 input The device contains a block of registers, including, n data input registers, a block of 2 valid registers, including m data output registers, a block of 3 interrupts, including -n + w interrupt control corners, devices 4.1, 4.2,., 4.p input , devices 5-), 5.2, ... 5.gp, switching units 6, 7; and 8, a block, 9 control transmissions, block 1D of the status registers and control, block-P address decoding, block 12 receivers, block 13 of transmitters, block 14 of the main communication with the computer, block-15 local control of peripheral devices. The device works in the following way. The device can operate in two modes: - in the mode of logical communication with a computer ("Communication" mode), - in offline mode ("Autonomous" mode). B. Mode “Connected peripheral devices (devices) 4 and 5 communicate with the computer independently of one another. Input-output is performed through the registers of blocks 1, 2, block 7, and blocks 12 and 13. The device is controlled and synchronized by blocks 10 and 11. The registers of block 10 include bits indicating the readiness of external devices, the occupation of external devices by performing input operations - output, completion of the input and output operation, as well as bits of command codes, errors and interrupt resolution. Some of these bits, namely, command codes, interrupt enablers are set by the computer, others are ready, busy, terminated operations and errors are set by block 15. The external device can issue an interrupt request only if the corresponding status and control register is set d, enable interrupt. The interrupt request is issued on condition that it is ready, when an I / O operation is completed, and with some errors. The interrupt requests of external devices are stored in the corresponding nodes of block 3, which can simultaneously store the interrupt requests of several external devices. Interrupt requests are issued to block 14 through block 8. In response to the request, block 14 and block 12 transmit a response signal from the computer. According to one signal from the computer, one interrupt request is serviced - the most priority of the existing ones. Blocks 3 and 8 provide sequential service requests according to priorities. When servicing an interrupt from external devices, a corresponding node of block 3 interacts with a computer, which issues an interrupt code via switching unit 7 and resets its interrupt request. The priorities of interrupt requests can be changed by switching in the switching unit 8. In the mode of communication with a computer, the device operates as follows. From block 14 to the device, block 12 receives the addresses of registers, data, control signals (type of operation — write or read, format of transmitted data — byte, half-word, word), accompanied by a synchronization signal. The addresses issued in block 14 are decoded by block 11 and, if the address given is the address of one of the registers of blocks 12 or 10, an entry is made in this register or its contents are read depending on the type of operation — write or read. Before starting an input or output operation, the computer pre-reads the status and control register of unit 10 of the corresponding peripheral device. If the device is not occupied and ready for operation, the computer can initiate an input-output operation in this device. When entering, the command code is sent to start the operation in the corresponding status and control register of block 10, after: The network reads data from the external storage medium (punch cards, magnetic tape recording, etc.) and loads its input register of block 1, and also sets the bit for completing the input operation in the status register and the control of block 10. If the interrupt enable bit was previously set in the corresponding state and control register of block 10, an interrupt request will be issued. After servicing the interrupt request, the computer reads the information loaded into the register of block 1. If the interrupt enable bit has not been preset, the computer will obtain information about the presence of data in the register of block 1 by reading the state register and controlling this device.

During the output, data is output to the corresponding output register of block 2 and the subsequent issuance of the command code to start the operation to the corresponding status register and control of the block 10. The device starts the output operation and outputs the contents of the output register of block 2 to external media (punched tape, electron beam screen). tube (CRT), etc.) and sets the bit to complete the operation in the status register and the control unit 10.

In the Link mode, block 9 blocks transmissions between the registers of blocks 1 and 2 and permits the passage of control signals from block 11.

Offline mode (set from the control panel) provides interaction between input and output external devices 4 and 5 without loading the unit 14. This is accomplished by the switching unit 6 and the transmission control unit 9. Block 9 blocks the writing and reading of the registers of block 1 and 2 and writing to the status registers and the control of block 10. The reading of the status and control registers is not blocked, so the information of these registers is accessible by a computer.

Transmission control is carried out by block 9, which, depending on the position of its mode switches (not shown in the drawing), carries out the respective gears and starts the device. Depending on the position of these switches; The data from one of the input registers of block 1 can be transferred to one or several output registers of block 2. At the same time, data from a certain input external device 4 is simultaneously output to one or several output external devices 5.

The first transmission is carried out by a start-up signal, which is generated in block 9 and transmitted to block 10. The start-up signal simulates in block 10 the effect of the "start operation" command.

Thus, the corresponding input external device 4 starts and loads its input register of unit 1. According to the input register loading signal, block 9 generates write signals to output registers and start signals of corresponding output external devices 5. After the output process is completed, output devices

5 issues an end of operation signal. These signals are transmitted through block 15 to block 9. Signals that arrived last, that is, from the slowest external device, are used by block 9 to generate a start signal from the input external device 4. The start is performed in the same way as from the initial start signal, which described above.

In addition, block 9 blocks the installation of readiness bits for external devices in block 10, as well as the installation of interrupt requests at the nodes of block 3.

It is advisable to use an interface device to connect several slow and medium-speed external devices that have relatively simple software and simple control, such as, for example, a typewriter, tape and card punchers, a line-printing device, an alphanumeric display, a tape cassette. magnetic tape, etc.

The organization of the device allows the CPU to be free from tasks such as preparing data on

punched tape, printing data from a magnetic tape to a line-printing device, preparing a magnetic tape, punched cards, etc. In addition, the device improves the performance of the computational system, saves the scrapping time in preparing the data, and increases the actual throughput of the trunk due to organization of transmission between connected external devices without loading the trunk

communication with a computer.

Claims (2)

1. USSR author's certificate number 490115, cl. G 06 F 3/04, 1972. 2. US patent number 3815099, cl. G06 F3 / 04, 1974.