JPS5849891B2 - How do you know what to do? - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the field of information exchange between a central unit and a peripheral unit, and more particularly to the exchange between a central unit and a peripheral control unit.

Connection systems are known in which a central device is connected to a number of peripheral devices by means of a so-called star connection, in which each peripheral device is connected to the central device by its own cable.

Other systems are also known in which a central device is connected to all peripheral devices by a connection layout in which a single cable or "bus" connects the central device.

In such systems, the task of managing information exchange is delegated to a central unit; therefore, that unit dedicates a significant portion of its processing time to managing peripheral devices.

Another disadvantage of these connection methods is that it is not possible to add peripherals or change the shape of peripherals without changing the electronic structure of the interface and the elements located in the central unit. It is.

Connection-related problems generally come in two forms: one is physical, due to the electronic nature of the different components, and the other is related to language and synchronization. .

Thus, connecting a printer or card reader to the same transmission line at will may be due to differences in interaction formats, response times of mechanical elements being too long, or due to system specifications, but rather due to differences between the central unit and peripheral equipment. This was not possible for some reason, such as the length between items being too long.

One example of widely applied data exchange is as follows.

In this example, the data is applied to the transmission line some time before the sampling signal is applied to ensure that the data is stable on the transmission line before it is accepted.

This time interval is the safety margin anticipated by the manufacturer at the design stage, taking into account the type of peripheral devices that will be connected to the central device and the maximum distance that they will be placed away from the central device. are equivalent.

Although such a system may be fully functional within the framework dictated by the specification, it may employ peripherals that are used with response times greater than those permitted by the specification, or It is easy to understand that there is a problem if the distance from the central device is greater than the distance from the central device where the device is located.

Of course, such a connection method can be made to work by increasing the safety time allowed between when data is applied to the line and the time it is sampled.

This can be done both in the central unit and in the peripheral units, but this requires considerable technical changes and installation costs.

So, without changing the electronics at the output stage of the central unit, each peripheral was given logic circuitry to give it a little more independence from the central unit, such as a printer, card reader, charting device, keyboard, etc. Attempts have been made to standardize the interface between the peripherals and the central unit so that very different peripherals, such as, can be connected to the same information bus.

Examples of such interfaces include French patents 1,5, 6, 6 and 6, currently under the name of Campanihanewelbre, Société Industrie Plurgénérale Electric.
1 7 7.

In this embodiment, each peripheral device has a connection collection consisting of a local control unit, an instruction register for storing instructions for transfer, and an order memory for providing the direction in which the data should be transferred. .

All peripheral devices are connected to the central unit by a single bus.

In the central unit, each control command to be supplied to one peripheral device is held in a specific register assigned to the peripheral, and the command is transferred to the register belonging to the peripheral by a control signal issued by the control device. be done.

In response to the command code, the central unit sends an enable signal which triggers a signal via the local controller requesting a character transfer, and the central unit then transmits a pulse to initiate the character transfer.

The fact that each peripheral has been given a connection aggregation helps to eliminate some of the drawbacks associated with the connections mentioned above, but it also allows the central unit to be connected between many peripherals that necessarily compete with each other. The fact that the transmission bus is divided does not relieve the central unit of its task of managing data transmission.

Thus, the central unit is required to act in a manner that allows any peripheral device to advance its use of the transmission bus on a time-shared basis in preference to other peripheral devices.

Therefore, this type of transmission becomes a limitation for the central unit in the final analysis.

In order to relieve the central device to a large extent from the task of managing the peripheral components, a peripheral control is in a position to discover the state of the peripheral devices at any time and to decide whether to use or not to use the functions presented by the peripheral channels. Attempts have been made to use the device.

It is thus an object of the present invention to provide an interface between a peripheral control unit and a central unit that is sufficiently versatile to overcome the problems of interaction formats described above and is not subject to the connectivity constraints found in the prior art. There is a particular thing.

The invention thus relates to a method for the exchange of information between a central unit and a peripheral control unit via a physical transmission channel, referred to in the following description as a PSI interface.

The signals exchanged at the channel interface are self-slaving and the channel uses service code equipment for initiating channel programs and for transmitting data along different logical channels between the central unit and peripheral units. use.

Other features and advantages of the invention will become more apparent on reading the following description taken in conjunction with the accompanying drawings.

FIG. 1 shows an information processing system, where 1 is a central processing unit consisting of a central unit main body and a human output device, 2 is a peripheral limb device 3, 4, 5, . . . n is a type of peripheral device.

The interface PSI, which forms the main part of the invention, provides the connection between the human power control device and the peripheral control device.

Although only one interface PSI is shown in FIG. 1, this number is not limiting; there may be a number of peripheral control devices, each connected to the same central device by an assigned PSI interface. This is what makes it possible.

All interface structures are Interface PS
It should be understood that it is the same as I.

The interface PSI is located in the central unit and peripheral units and provides a number of functions as shown in FIG.

In FIG. 2, the symbols represent connected line signals and have the following meanings (the head of each arrow indicates the direction in which transfer occurs).

SCI is an initial value setting signal for the service code.

SEO is an output permission signal.

This indicates that the I/O controller is ready to receive service codes.

STI and STO control data transfer on the interface.

TMI is a signal indicating that the peripheral control device has finished transferring data.

TMO is a signal indicating that data transmission from the central unit has ended.

CPW is a signal that advises the peripheral controller that a channel program is waiting in the hardware, ie, the firmware of the central unit.

INW is a signal used in the input/output control device to notify the peripheral control device that a command is in a standby state, so that it can be transmitted to the peripheral control device.

ISO is a signal that indicates that an error has been found in the transfer sequence and informs the peripheral controller of this fact.

RSO is a signal that restarts the peripheral controller and places it in a known state.

In particular, this signal is capable of immediately stopping any language in progress between the peripheral controller and the human output controller.

In the OPO, the crowd control device connected to the interface is in operation. This is a signal indicating that

OPI is a signal indicating that a peripheral control device connected to the interface is in an operating state.

NTI means that the peripheral controller has at least one channel.
This is a signal that is "1" whenever a program is executed.

REI is a peripheral controller executing a channel program and a special order 4? (its channel size)
This is a signal that becomes "1" whenever a signal is received.

DAO is a signal that allows diagnosis of interface PSI.

The data lines allow one data byte to be transferred in either direction.

These are 9 leads, i.e. 8 data leads and 1
Consists of multiple parity reads.

According to the agreed conventions, the transfer of information from the peripheral controller to the central unit is called a read operation, and the transfer of information from the central unit to the peripheral controller is called a write operation.

A read operation consists of either data originating from the peripheral in transit or data provided by the status of the peripheral or information combined with a service code.

Service codes are instructions transferred by a peripheral device to an input/output controller of a central unit to carry out a channel program for the peripheral controller.

A write operation is a record of the carrier of a peripheral item or data prepared for a peripheral controller register, or a central unit input/output controller to a peripheral controller for channel instructions or input/output controller transfer control. This transfers one of the instructions given by .

Human output operations at the PSI interface are represented in channel programs contained within the central unit, and peripheral controllers command input-output operations as a function of instructions contained in their respective channel programs.

The peripheral controller must therefore benefit from accessing the channel program by using the channel program pointer and has various operating methods,
For example, a channel program is executed by reading an instruction to set an initial value for data transfer, or by transitioning to a new instruction.

The mode during which this channel program is being executed is determined by a service code, and the instructions contained in the channel program are transferred to the peripheral control device in accordance with the service code.

The service code can have a meaning, for example, as an initialization for a new program, an initialization at the beginning of a data transfer or its retrieval, or an initialization for an input/output command.

Communication between main memory and conventional peripheral items occurs by means of logical channels using physical channels.

Each program contains identical logical channels on which input/output instructions are to be executed.

The number of logical channels refers to the functional group that connects all information that may be storage areas, peripheral devices, peripheral items, etc., and that passes through the interface PSI to the appropriate program channel. It is something.

These logical channels allow a high degree of language flexibility in the interface, thus allowing multiple channel programs to be multiplexed through the same interface, allowing multiple channel programs to be advanced simultaneously. It has become.

Similarly, multiple logical channels may be associated with the same item of peripheral equipment.

This latter feature is useful when a number of operations on the same item of peripheral equipment must be carried out simultaneously, as in certain sorting machines, and especially in banks where the operation of reading the check digits and the transport of the check occur simultaneously. This is particularly effective when sorting checks.

Other examples could be given, but would probably go beyond the scope of the description of the invention.

Manpower/output control devices thus belong to the category of special instructions for carrying out manpower/output operations known as "channel commands".

These instructions collectively or six-channel programs form a 6-channel program whose function is to address information to perform a series of operations related to one item of peripheral equipment.

The channel program contains LC logical channels on which input/output operations are to be performed.

The structure of a channel program consists of a channel program heading, which consists of four words: the first word corresponding to the channel program absolute address CPAA, followed by the channel command manual CCE.
formed from.

Each channel command consists of two words: a first word called ccwo and a second word of CCW.

FIG. 3 shows this configuration.

Channel program headings contain the following information:

1. The number of channels associated with a channel program consists of a logical channel number LC and a number PC called physical channel number corresponding to the hardware of a special interface PSI.

It will be understood from the above description that the central controller may provide n interface PSIs to n peripheral controllers.

2. The priority at which channel programs should be executed and the comparison function made with other channel programs.

3. The address (C1, DI) of the signal to which a certain message is to be transmitted during the execution of the channel program.

4. Information indicating the area in which details of the status of peripheral items can be stored.

Channel program heading format is 4th
It is shown in the figure.

The channel command input CCE performs one input/output operation on one item of peripheral device.

The two words are 1. channel instructions 2. ″Flag area 3. address information Contains.

The format of the channel command is shown in FIG.

The various phases of executing a channel program are as follows.

1. connection phases.

In this phase, a channel program is connected to its associated logical channel.

Logical channels are placed in a queue of logical channels that are already connected to their channel program.

2. execution phase.

In this phase, the logical channel associated with the channel program is removed from the waiting queue so that the peripheral controller executes the channel instructions contained in the channel program.

3. End phase.

The peripheral controller forwards a message indicating "end of event" to the input/output controller associated with the central unit.

These various phases will be referred to in the remainder of the detailed description of the invention and will be helpful in understanding the description of the information exchange procedures in the interface PSI.

FIG. 6 is a time diagram showing the data being transmitted in read mode (data being transmitted from the peripheral device to the central device) and the principle used for the exchange in this case.

Signals STI and STO control the transfer of data across the interface.

Signal STI is generated at the same time data is applied to the transmission line.

When the input/output controller of the central unit is ready to receive data, it transmits a signal STO.

When the peripheral control device receives the signal STO, this is the signal ST.
causing I to go to zero, the effect of which is to begin sampling the data and transmitting it to the input buffer of the input/output controller associated with the central unit.

A drop in STI to zero will instead cause STO to drop, also erasing data from the transmission line.

Figure 7a shows an embodiment of the invention implementing this method.

The circuit called SI is a memory device with two inputs X1 and X2 and one output X.

This storage device has the following characteristics.

That is, if X1 goes from O to 1, the output X goes from O to 1 and remains at 1.

If X, returns to O and enters? When X2 goes from O to 1, the output X goes from 1 to O if it was already 1, which is
It happens even if 1 is 1.

The complete matrix for each face is shown in Figure 7b,
The stable state is marked with a circle.

The reduced matrix for each phase is shown in Figure 7c, and the matrix showing the quadratic changes is shown in Figure 7d.

It will be appreciated that there is only one quadratic change and its state matrix is the same as that of the output X.

Therefore, the equation for output X is X=XX2+X1X2-XX
2.X1X2.

Output X provides the STI signal in FIG.
is excited by the signal STO.

The human power X1 receives the initialization pulse of the signal STI.

The signal STI travels from the peripheral controller in the direction of the central unit through its interface and connects the two inputs NAND (
NOT AND) is received at one input of circuit A1.

Circuit A is enabled at its secondary input by an "input/output controller available" signal.

When activated, the result is that the signal STI is applied to the output of the amplifier A2, thereby generating the inverted signal STO to the interface PSI.

The rising edge of the signal STO is detected at the input X2 of the memory M(SI), the effect of which is to return the signal STI to zero.

When the falling signal STI is detected by the circuit A1, the signal STO falls again.

FIG. 8 shows a means of employing a data transmission method, which represents the bidirectional nature of the exchange.

It is understood that the peripheral controller and central unit switching logic is fully balanced on both sides of the interface.

The direction in which data is transmitted is controlled by the "read" or "write" states (indicated by R and W in the figure), which are microinstructions for the microprocesses to be executed.

The order in which the signals STI and STO are transferred is STI and STO.
Depending on the read or write operation on the interface PSI during the entire time that the signal is located by the equation STI+STO.

Data is received into the buffer when the STI returns to zero.

The main features of the information exchange method between the central unit and the peripheral pedestal units are as follows.

0. Its bidirectional.

That is, read and write operations occur on the same interface line.

1. Sampling signals STI and STO are mutually constrained.

2. Data is simultaneously present on the line as a sampling signal.

This concurrency eliminates the problem of optimizing the tolerance limits required during data transfer and sampling signal generation in the prior art.

3. Data is accepted into the buffer register only after the passage of three signals through the interface.

The first pass is the transmission of the signal STI. The second pass is a response with signal STO.

The third pass is the transmission of the attenuated end of the signal STI.

In this way, there is no possibility of malfunction because the sampled data is stable on the transmission line associated with the interface PST.

4. The above-mentioned features mean that no special precautions need to be taken when connecting the central device to the remote peripheral control device, which allows a connection scheme that is completely independent of the length of the connection.

5. The rate at which data is transmitted across the interface PSI in bytes/second is precisely related to the length of the cable.

If tc is the response time of transmission, trL is the response time of reception, and tc-L is the time required to send along the cable, where tc is given in meters/second,
L is the length of the cable, given in meters),
The time TD required to pass through the interface is TI)
=Td+tr+tcL.

If N is the number of bytes transmitted, the transmission rate is N
(2Ti is 4 T1 of STI and STO + 2 T i preparation time).

The units of magnitude are given in the numerical examples below.

N=1, L=30 meters, td=20ns, tr=
2 5 ns, ti = 1 8 ns, tc = 5.
3 ns meters, TD=204 ns, 4 TD+ 2
T i =852 ns, so the transmission rate is 1.17 Mbytes/sec.

The exchange of information in the interface PSI is controlled by microinstructions contained in a memory associated with the peripheral controller.

When a peripheral controller wishes to interact with the central unit's manpower/output pedestal, it will execute a micro-instruction+FSIO with a service code specifying the nature of the language that is about to occur.

This would in particular be the start of a new program, the start movement for data transfer, the start end of an accident notification.

Service codes are stored in various C
Provides access to CE continuation content.

The table shown in FIG. 9 gives the structure of the service code used in this case.

Each service code is represented by an 8-bit word.

That is, the four lowest weighted bits are
Other more heavily weighted bits are shown along the Y-axis.

A particular service code is obtained by combining its X-axis bits with its Y-axis bits.

The I/O controller receives a start service code to start or perform a new channel program.

Line CPW at interface PSI is thus activated.

The service code is transmitted along the data line interface.

The various channel programs are drawn in the waiting queue and with the channel order and flags included at the beginning of the channel program's CCE in the header of the channel program being the first one to appear from the highest priority waiting queue. Found waiting queue L
The input/output control device is extracted from the c number.

The I/O controller sets two channel program pointers, CMP and CWP.

CMP is the first CC in the first CCE (order manpower)
W (channel order word).

CPW refers to the first CCE.

Each time execution of a channel command is completed, the peripheral controller emits a service code to shift the channel command pointer by changing the values of CMP and CWP.

If the channel order in the first CCE is a data transfer or the sequence wrapped in the service code for shifting the channel program pointer indicates a shift that is followed only by the transmission of the channel order to be transferred. For example, the peripheral controller emits a start service code for data transmission.

No data transfer between the I/O controller and the peripheral controller can occur before the peripheral controller has completed the transfer of the data transfer initiation service code.

The sequence for starting and for carrying out the channel program is thus:

The input/output controller sets the CPW at 1.

The peripheral controller emits a start service code for the new program.

The I/O controller extracts the logical channel number and the first ICCE from the waiting queue and forwards them to the peripheral controller which carries out the first ccE.

The peripheral controller then emits a service code that shifts the order pointer.

The next CCE, perhaps a read for data transfer, is then transferred to the peripheral controller.

A start service code for data transfer is then transferred from the peripheral controller to the input/output controller.

That data is then transferred when the CCE is carried out and a service code is again emitted by the peripheral controller to shift the channel order pointer.

The form of CCE for data transfer is shown in FIG.

The channel order associated with this particular CCE is PCU
either control operations in the memory or transfer data between peripheral devices and main memory.

The area marked 6 counts '' gives the size, in bytes, of the area in the main memory buffer into which transfers will occur to or from the main memory buffer.

The absolute address in the main buffer memory is an absolute address of the size of the first byte of the area of the main buffer memory for data transfer to which the corresponding channel order is associated.

FIG. 11 shows the timetable associated with the initiation procedure and results for a new program.

The start service code for a new program comes from the peripheral controller in response to a signal cPw to cause a replication of the logic channel number and the first channel order manual CCE to be transferred from the central unit to the peripheral controller.

In the figure, the signal CPW is the start signal SC for the service code.
I, which generates SEO and transfers SEO along the service code data path by the peripheral controller for starting a new program.

According to the related data exchange principle described above, this service code is generated at the same time as the sampling signal TMI is generated.

The latter causes the signal STO to rise, which causes the signal TMI to recur to zero, which in turn causes the central unit to receive the service code and causes the signal STO to fall to zero at the central unit.

When the signal STO falls, the signal SCI sequentially falls,
The falling edge of signal SCI causes signal SEO to fall, thus causing the service code to disappear from the transmission bus.

When a new program is started, the central unit stores the first to last bytes contained in the channel program, the first corresponding to the number of the logical channel associated with the channel program, and the second to last corresponding to the number of the logical channel associated with the channel program. gives a sequence of bytes corresponding to .

It can be seen from the figure that each byte is transferred along the data path simultaneously with signal STO and that receipt of a byte at the peripheral controller occurs when the peripheral controller detects that signal STO has returned to zero. .

According to the related data exchange principles discussed above, three cycles of transmission along the PSI line elapse before the transferred data is effectively accepted.

When the last byte of a channel program is transferred, signal TMO replaces signal STO to indicate that the included byte is the last one included in the channel program.

FIG. 12 shows a timetable of the initiation procedure for data transfer.

The service code for data initiation is used by the peripheral controller for the initiation or resumption of data transfer across the interface PSI as indicated by the content of the information previously transferred to the peripheral controller.

The logical channel number may or may not be transmitted with the service code.

To start a data transfer, the peripheral controller sends a signal SC
Set I to 1 (initialization code),
The central unit thereby sets the signal SEO to 1.

By receiving the peripheral control device SEO it places a service code on the data line and at the same time sends out a sampling signal ST.

Upon reception of this latter signal, the central unit generates a STO signal, which, when received by the peripheral control unit, generates a signal S
Set TI to zero.

When the falling edge of signal STI is detected by the central unit, the service code is sampled and received by the central unit.

The falling edge of signal STI in turn causes signal STO to fall to zero.

At the same time as the logical channel number is emitted by the peripheral controller, signal TM- is emitted instead of STI.

The logical channel number reception sequence is the same as the data transfer initiation sequence.

The falling of the signal STO causes the data date to be transferred from the peripheral control unit to the central unit.

That data is transferred at the same time as the STI is transferred,
Acceptance occurs when STO returns to zero.

During the process, the following two contingencies may occur: An asynchronous accident occurs in a surrounding subsystem.

- Request a channel program incident program by having an incident notification bit in the ``flag field of the CCE.

These sequences are to generate a service code that initiates an accident notification.

If the accident notification message cannot be stored in the accident notification waiting queue, the input/output controller sends a signal IS.
0 and provides instructions during notification of the peripheral controller so that the message can be stored in the peripheral subsystem.

If the message can be stored, the I/O controller systematically stores the message.

Service codes apply to logical channel numbers and surrounding conditions.

These conditions are accompanied by a summary statement of 6 through 3 with an accident notification message to the ``Software''.

The end of start service code is emitted by the peripheral controller to bring the channel program to a close.

The logical channel number may or may not be accompanied by this service code.

FIG. 13 shows a service code for initiating accident notification according to the principle of self-slavery between transferred information according to the present invention;
and a time table of the sequence of service codes for the end of initialization.

It can be seen that signal TMI is transferred at the same time as the last byte of the sequence is released.

A channel program can be terminated normally or abnormally: in the first case the last CE transferred
E marks the end of the channel program, and in the second case execution of the channel program ceases when the intermediate CEE is carried away.

In both of these cases, the peripheral controller transfers to the central unit a logical channel number LC and a service code for termination initiation, which is followed by the transfer of 6 summaries ``'''.

The sequence illustrating the phase of termination of the channel program is shown in FIG. 13 and is the same as that of the incident notification.

Figures 14 and 15 show the arrangement for exchange at interface PSI.

FIG. 14 shows an example central device interface.

In this figure, the signals STI and STO are exchanged on the one hand and TIV on the other hand.
Exchange of fI and TMO takes place at the interface.

The circuitry required to generate the signals TtVII and TMO is identical to that which generates the signals STI and STO already described.

The data bus is data reference D. carry it to D.

When the service code is initialized, the face counter Oφ is transferred to the buffer register T.

, switch to T4. The progression of that face counter is governed by the formula SEO(STI+TMI).

Buffer register T. Data reception ceremony ST to Kara T4
Occurs when the state indicated by I+TMI ceases to exist.

φ. φ4 represents the five faces of the face counter.

The face φ0 is equivalent to an occurrence of a service code, the face φ1 is equivalent to an occurrence of a logical channel number, and φ
3 is equivalent to the second state, and φ4 is equivalent to the fourth state.

The presence of these faces allows data to be transferred to the buffer registers.

Once in register T.

The service code stored in is decoded by a decoder DSC to indicate to the processing element the nature of the received service code.

This includes, for example, the lines SCIUP (service code for setting a new program), SCT (service code for end of current program), SCE (service code for event notification), SCTD (service code for data transfer). code) etc.

Register T1 contains the logical channel number;
2 contains a first state of the periphery, register T3 contains a second state of the periphery, and register T4 contains a third state of the periphery.

Depending on the nature of the received service code, reading data performed by amplifiers A1 to A7 or writing data performed by amplifiers B1 to B7 will be necessary for the processing elements.

A signal CPW is generated by the processing member to indicate that a channel program is pending.

Signal SEO is generated by a "JK" flip-flop which goes to 1 when signal SCI rises and goes to 0 when that signal returns to zero.

During a write, data is gated by the formula STO+STI+TMO.

FIG. 15 shows the interface on the peripheral control device side.

The logic sequencing device S receives signals STI, STO. It also has the job of exchanging TM■ and TMo.

When present, signal CPw connects the flip-flop to SCI.
Initialize to.

The flip-flop is reset by the processing member.

Data is written by amplifiers A1 to A7 and read by amplifiers B1 to B7, using the formula STO+TMO+
Controlled by STI.

Signal SEO is transferred to the processing element and initializes data transfer.

It is perfectly clear that the above description of the method and apparatus is given by way of non-limiting example and that modifications can be envisaged without departing from the scope of the invention.

Term Software: A combination of means created for effective use by a computer.

Elements of programs in various formats It consists of

Roomware: Fixed or permanently readable memory and its associated circuitry, memory used to store microprograms for the purpose of invoking a function to be performed, such as the execution of instructions in a program or Used to trigger repetitive functions such as peripheral device operations to be performed.

It consists of all the physical components of a computer, whether they are hardware devices, elements, or the arrangement used.

Bus: A single line used for the distribution of electrical signals.

Bytes: Multi-Bullet (Multiple Bits) Process:
Non-simultaneous execution of a series of commands.

Also, the program and the sections that are required to be carried out. Connection with the eyes.

Semaphore: Sending a certain signal to inform other "processes" that a certain event has finished in a "process" with a weak check used to synchronize many processes running at the same time. It is possible to send a message to "Semahou" inquiring whether a certain process or event has finished.

Flag: A binary position or character whose function is to print that the zone has been reversed for a data item, and whose length is such that the flag is encountered when transmission of the item is requested. is variable to indicate that the last character in is actually transferred.

X: Microsystem of reciprocal operations of X in pool algebra.

Micro clearing system JK flip-flop
= A binary flip-flop is set to binary 1 by supplying a binary 1 to its input terminal J, and is reset to zero by supplying a binary 1 to human input terminal K. .

Summary state: A state that is prevalent in one device.

Initializing: To prepare in terms of starting work.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the location of the interface PSI through which information passes between the central unit and the peripheral control unit. FIG. 2 shows the physical channels associated with the interface PSI through which information passes between the central unit and the peripheral control unit. FIG. 3 shows the structure of the channel program. FIG. 4 shows the format of channel program headings. FIG. 5 shows the format of channel name+CCE. FIG. 6 shows a time diagram during transfer in read mode. Figure 7a shows an embodiment of the invention using this method. FIG. 7b shows the state matrix of the memory M (SI) shown in the day Ia diagram. FIG. 7C shows the reduced state matrix of the memory M(S I ). FIG. 7d shows the modified quadratic matrix associated with the memory M(SI). FIG. 8 shows how the present data exchange method is implemented, representing the two-way nature of the transformation. FIG. 9 is a table showing various initial value setting service codes. FIG. 10 shows the format of a CCE containing instructions for data transfer. FIG. 11 is a time diagram of the initial value setting procedure for a new program. FIG. 12 is a time diagram of the initial setting operation for data transfer. FIG. 13 is a time diagram of the initial sequence for event commands. FIG. 14 shows a device implementing the data exchange method of the present invention in a central unit. FIG. 15 shows a device in which the data exchange method of the present invention is implemented in a peripheral control device.

Claims (1)

[Claims] 1 ``!'' The two signals STO and STI indicate the direction of transfer (
Read from PCU to CPU or from CPU to PCU
A bidirectional exchange of information via a transmission channel between a central unit (CPU) and a peripheral control unit (PCU), including the storage of channel programs, which is used to determine the data (written to the program) and sample the signal. a signal STO is transmitted at the same time that the data is transmitted along the data line from the central unit (CPU) to the peripheral control unit (PCU) for controlling and sampling the data; and after three consecutive transmissions (in this S, three consecutive transmissions means one to the central unit (CPU) and one to the peripheral control unit (PCU)).
), and the second is to create and send a signal STO between the peripheral control unit (PCU) and the central unit (CPU).
The third is to send the falling edge of the signal STO based on the detection of the signal STI by the central unit (CPU) between the central unit (CPU) and the peripheral control unit (Pct). It is characterized in that when the landing gear detects that the signal STO falls, this data is instantly accepted by the peripheral control device, and the same signals STO and STI are used from the peripheral landing gear to the central device; A central processing unit characterized in that an STI signal appears on the data line at the same time as the data, and acceptance of the data by the central unit occurs when the falling STI signal is detected in this same central unit (CPU). A method of exchanging information between the device and peripheral control devices.