JPH0199149A - Bus ID automatic identification device - Google Patents

Abstract

PURPOSE:To automatically identify a bus ID number even if the overlap of the bus ID number exists in either a phase for acquiring a bus or the phase for selecting the other party and to change the ID number by providing a self-ID number holding means and other master ID number holding means. CONSTITUTION:Means 14 and 16 are provided, which variably set and hold the self-ID number of a master device 1, when a bus 2 is not used by the master device 1, an action for acquiring the bus with some other master device is supervised, the bus ID number used at that time is fetched to other master ID number holding means 17, and when the number and the self-ID number coincide, the self-ID number is changed. Thereafter, after the master device 1 acquires a bus using right, when the coincidence of the self-ID number and the ID number of the other party slave device fetched to a slave ID number holding means 18 is detected at the time of selecting the other party slave device, similarly, the self-ID number is changed. Thus, even if a setting mistake to cause the overlap of the number exists, the bus ID number of the master device can be changed, and the actions for acquiring and selecting the bus can be executed without an operator.

Description

[Detailed Description of the Invention] [Summary] s is a ■/○ interface for small computers.
Regarding the bus ID number automatic identification method in the cs i bus system, even if there is a duplicate bus ID number in either the bus acquisition phase or the partner device selection phase, it will be automatically identified and the ID number will be changed. The purpose is to provide an automatic bus ID identification system that provides a unique bus ID for each bus consisting of data lines and control lines.
A plurality of numbered master devices and a plurality of slave devices are connected, and the bus is transferred through a phase in which the master device acquires the right to use the bus using the bus ID number, followed by a phase in which a partner slave device is selected. In a bus rD automatic identification method in a bus system that can be occupied, the master device is equipped with self-ID number holding means, ID number changing means, and other master ID number holding means, and the master device changes the ID number of the setting switch to the above when the system starts up. The ID number is stored in the own ID number holding means, and when this master device is not using the bus, it takes in the ID number of another master device that was used in the bus acquisition operation by another master device, and compares it with its own ID number. If the device loses, its own ID number is changed by the changing means, and if there is a loss in the ID number in the operation of the phase of selecting a partner slave device, the device is configured to change its own ID number and perform the selection.

[Industrial Application Field] The present invention is an I10 interface for small computers.
The present invention relates to an ID (Identifier) number automatic identification method in a bus system of System Interface.

Recently, the SC3I bus, which has 8 data lines (8 bits), 1 parity line, and 9 control lines, became known as a high-performance 110 interface for small computers. .

With this interface, the devices connected to the bus are
There are two types of devices: a device called a master (or initiator) that has a function of generating instructions, and a device called a slave (or cuget) that receives and executes instructions from others. Bus control of this interface is useful when multiple master devices acquire the bus,
When a master device that has acquired a bus selects a slave device, priority is determined using bus ID numbers assigned to each device in advance, and priority is given to devices with higher numbers.

In such a bus control system, when assigning bus ID numbers to each device or when setting hardware (switches, etc.), the same number may be set to multiple devices by mistake. It would be desirable to be able to automatically identify and deal with such errors.

[Conventional technology] An explanatory diagram of a conventional example is shown in FIG.

FIG. 3A shows the system configuration of the SC3I, and in the figure, 30 and 31 are initiators 9 (INTT), which are master devices, and targets (TARG) 32 to 34 are slave devices, respectively. , 35 represent a bus. The bus 35 has a data line of DB (data bit) 0.
~ REQ (Request), ACK (Ack) as 8 lines of DB7, parity line and control line.
knowledge), BSY (Busy), S E L
(Selection) etc.

When an initiator wants to give a certain command to a target to execute an operation, it must first win over competing operations with other initiators in the arbitration (acquisition) phase.

FIG. 3B shows the arbitration phase when requests to use the bus are generated from both inishes 30 and 31.

CB), when no device is using the bus (bus free phase), the inishke 30 sets "1" to the control line BSY as a signal indicating a bus request.
C on the data line to indicate your ID number 7 at the same time.
Set B7 to 1″.

On the other hand, if a hash request occurs in inishake 31 at the same time, it sets "11" on control line BSY (if it has already come out from inishake 30, there is no change in the signal level on the line), and at the same time sets its own ID number 3. To indicate this, set "1" in the data line DB3.

When a certain period of time has passed since the first BSY signal was generated,
30.3 for each initiator that participated in the arbitration.
1 searches the data line to see if there is an ID number larger than its own ID number, and if it finds that it has the largest number, it means that it has won, and "1" is sent to the control line SEL. At the same time, the BSY signal and the "1" output of ID number 7 are set to "0". The losing initiator then sets the display of its own ID number and the output to the control line BSY to 0''.

In this arbitration phase, if inishes 30 and 31 hold the same ID number, it is assumed that both have acquired the right to use the bus, and each moves to the next selection phase and enters an error state. In the end, neither of them will be able to use the bus.

The initiator 30 that wins the arbitration then moves to a selection phase to select a target. As described above, when the arbitration competition is won, the SEL signal is generated from the inishke 30 and the selection phase is entered, and an example in which the selection is successful is shown in FIG. 3(C).

As shown in the figure, in this phase, the inishke 30 writes “1” to the DB 7 to display its own ID number 7.
At the same time, use the DBI to display target 33 (ID number 1), which is the target device to which you want to issue commands.
Put an “l” on it.

Each target connected to the bus receives a SEL signal
During the selection phase when the BSY signal becomes "0", you can use 8 to determine if your ID number becomes "1". If so, the BSY signal is set to "1" and used as a response signal.

Furthermore, FIG. 3(D) shows an example in which the selection is unsuccessful. In this case, from initial shake 3°, your I
Set “1” in DB7 as the D number, and
1" is written in the same DB7 as the D number. In this case, each target checks all eight data lines DBO-DB7, and if the line with "1" written on it is 2 trees, and it is his own ID number. If it is determined that the target is set, the target will return a response, but if the ID numbers are duplicated as in (D), it will be found that only one ID number is displayed, and the target will not return a response. No. By the way, the same applies to the case where three ID numbers are displayed.

[Problems to be Solved by the Invention] As mentioned in the explanation of the conventional example, in the case of acquiring the right to use the bus (arbitration), multiple master devices (
If ID 1 is duplicated between two initiators, an error state will occur when there is competition for bus acquisition between them, and the problem is that the bus cannot be used after all.

Furthermore, if duplication of ID numbers occurs in the operation of selecting a slave device (target) of the other party, there is a problem that selection cannot be performed and the bus cannot be used.

Conventional bus ID numbers are controlled by dip switches, setting pins, relays (operated according to instructions from the terminal), etc. on the circuit board, and are composed of so-called hard switches, which prevent bus ID numbers from being duplicated. However, this is detected by visual inspection by an operator, and it is difficult to automatically identify duplicate bus ID numbers.

The present invention provides a bus ID that automatically identifies and changes the ID number even if there is a duplication of bus ID numbers in either the bus acquisition phase or the partner device selection phase.
The purpose is to provide an automatic identification method.

[Means for solving problems] FIG. 1 shows a basic configuration diagram of the present invention.

In the figure, ■ is a master device (inishek), 10 is the main unit of the master device, such as a host computer, 11 is a bus adapter, 12 is a bus acquisition/selection means, 13 is an ID control means, 14 is an ID number change means, and 15 is a bus Bus monitoring means when not in use; 16, self ID number holding means; 17, other master tD number holding means; 18, slave rD number holding means; 19, a lotus ID number setting switch; and 2, the bus.

Although not shown, other master devices and a plurality of slave devices (targets) are connected to the bus 2 in FIG. 1.

The present invention provides means for variably setting and holding the self-ID number of the master device, and when the master device does not use the bus,
It monitors bus acquisition operations by other master devices, captures the bus ID number used at that time, and uses that number and its own ID.
If the master device matches the D number, it changes its own ID number, and after the master device acquires the right to use the bus, when it detects a match between its own ID number and the ID number of the other device when selecting the other slave device, it changes the self ID number in the same way. This is to change the ID number.

[The main body 10 of the working master device (initiator) 1 is a processing device such as a host computer, and the bus adapter 11 connected thereto has the function of an interface between the initiator main body and the bus.

The master device is provided with a switch 19 for setting a manually settable bus ID number, and the contents of this switch 19 are sent to the self-ID number holding means 16 when the master device starts up (powers on).

If there is no bus acquisition instruction from the master device main body, the bus monitoring means 15 monitors the bus acquisition operation performed on the bus 2 (determined by the control line), and the ID number at that time (in the acquisition operation, the master device The ID number is output) is read from the data line and stored in the other master ID number holding means 17, and the ID control means 13 compares the number with the contents of the own ID number holding means 16. If they match, the own ID number is output. is changed by the ID changing means 14 and stored in the own ID number holding means 16 again. Note that the other ID number holding means 17 has a holding capacity corresponding to the number of master devices connected to the bus 2. (When two master devices are connected, each master device holds one other master ID number).

Also, when another master device moves from the bus acquisition phase to the partner selection phase, the master device that is not using the bus will
Monitors the D number, captures the ID number used when another master device selects a slave device (the ID number of the master device and the ID number of the other slave device are output at the same time), and holds the other party's ID number as the slave ID number. The information is stored in the means 18. This slave ID number is also compared with the contents of the self-ID number storage means 16, and if they match, the self-ID number is
The D number is changed by the changing means 14.

When the master W2 body 10 issues a bus acquisition (arbitration) instruction to the bus adapter 11, the bus acquisition/selection means 12 instructs the bus 2 to assign its own ID number to the bus 2 based on the contents of the own ID number holding means 16. “1” is placed on the corresponding bit line among the 8 data bit lines.
” and sets the control line BSY to “1” to issue a request.

At this time, when a similar request for bus acquisition is issued from another master device, the data bit line is checked to detect whether it has priority over itself. At this time, the data bit is “1”
The other ID numbers are checked using a certain line to detect which one has priority.

In this case, through the above-mentioned monitoring operation, each master device acquires the ID numbers of other master devices, and if the ID number of the other master device matches the own ID number, the self ID number has already been changed at that time. ID in the acquisition phase
No duplication of numbers will occur.

When this master device acquires the right to use the bus and subsequently selects the other slave device,
This time, it is checked whether the ID number of the other slave device and the self [D number] match, and if a match is detected, control is executed to change the self ID number.

Even if you change the number and start the bus acquisition/selection operation again, if there is a duplicate number, all ID numbers 0
If eight [D numbers] from 7 to 7 are used, a hard error occurs and an error output occurs.

[Embodiment] The control flow of an embodiment of the present invention is shown in FIGS. 2(al) to 2(C1).

FIG. 2 (al to FIG. 2 (C1 is the bus acquisition/selection control means 12 of the bus adapter 11 in the basic configuration of FIG. 1)
, bus monitoring means 15 and ■DIII control section 13 ring section 13
This figure shows the control flow of the bus adapter.

Figure 2 fat and Figure 2 (bl) are the control flows executed when the master device does not use the bus, and Figure 2 (C1
shows the control flow when the master device issues a request for bus acquisition/selection.

Figure 2 (In Ml, the master device is powered on (
(stands up), initialization is performed, and the bus ID number that was set in hardware at this time is set to self-ID number register 0 (corresponds to self-ID number holding means 16 in Figure 1).
is set to Note that the register is indicated as Reg in the figure.

Next, monitor (scan) the state of the control line of bus 2 (see Figure 1) to see if a bus acquisition request state has occurred. bit line) (210, 22
0).

Then, it is checked whether the captured ID number has already been registered in the other master ID register 21 (corresponding to the other master ID number holding means in FIG. 1), and if it is not registered, it is registered (or updated), Next, compare the contents of the other master ID register 21 with the contents of the self ID number register 20, and if they match, subtract 1 from the value of the self ID number register 0, and store the result in the self ID number register 20. Store again (260).

After this, move on to Figure 2 (bl) and select from other master equipment (
control line (S selection phase)
EL), and if there are any, the two ID numbers outputted to the data line at that time are taken in (280).

Next, since one of these two ID numbers is the master ID number, compare it with the contents of the other master ID registers 21, and if they match, remove that number and select the other ID number (the ID number of the slave device). and the slave (S 1 a
) is stored in the TDD number table 22 (corresponding to the slave ID number holding means 18 in FIG. 1) (300).

The slave ID number in this table 22 is then compared with the self-D number register 20, and if they match, the value in the self-ID number register is minus 1 and stored in the same register again. Thereafter, if a bus acquisition request is not generated from its own master device, the process returns to the original step 210 in FIG. 2 (al), and if a bus acquisition request is generated, the control flow in FIG. 2 (C1) is started.

In FIG. 2 (C1), this master device outputs a bus acquisition request with the number set at that time in its own ID number register 20 (410). When the bus is acquired, the master device sends its own ID number and the other slave device. A selection operation is performed by outputting the ID number of the master device (430).If the selection operation is successful, the acquired bus is used to transfer commands from the master device to the slave device (target) and perform various processing. (460).

If the selection fails, the bus is released and other devices are allowed to use it, while the contents of the self ID number register are compared with the ID number of the other slave device (the other device for which the selection failed) to see if they match. If the slave ID number is
a) (Register in the D number table 22.

Next, the own ID number that matched the other party's ID number is minus 1 and stored in the own ID number register again.

After this, it is checked whether the changed self-ID number matches any of the multiple slave ID numbers registered in the past (500), and if it does not match, it is further checked whether all the numbers have already been registered. , if it has been registered, an output is generated as a hard error, and if it has not been registered, the bus acquisition request operation is performed again using the changed contents of the self ID number register.

[Effects of the Invention] According to the present invention, each bus ID of a master device (initiator) or slave device (target) connected to a bus
Even if there is a setting error such as duplicate numbers between numbers,
Bus acquisition and selection operations can be performed by automatically changing the bus ID number of the master device without operator intervention.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the basic configuration of the present invention, FIG. In Figure 1, 1: Master device (inishek) 10: Master device main body 11; Bus adapter 12: Bus acquisition/selection means 13: ID control means 14: ID number changing means 15: Bus monitoring means 16: Self rD number holding means 17: Other master ID number holding means 18 Nisle ID number holding means 19: Bus ID number setting switch 2: Bus patent applicant Pfn Co., Ltd. Agent Patent attorney Fumihiro Hase (two others) passed away - The center 4 of 1st calf 1r3I is also used, and the autopsy name is 70-(11゛ 44
Daiyo 11] Part 2 (2) (b) - 〇 〇

Claims (1)

[Claims] A plurality of master devices and a plurality of slave devices, each assigned a unique bus ID number, are connected to a bus consisting of a data line (110) and a control line (111), and the master device controls the bus. In a bus ID automatic identification method in a bus system in which a bus can be occupied through a phase of acquiring bus usage rights using an ID number and a subsequent phase of selecting a partner slave device, a master device (1) is provided with self-ID number holding means. (16), ID number changing means (14), and other master ID number holding means (17), the master device (1) transfers the ID number of the setting switch to the self ID number holding means (16) when the system is started up. When this master device (1) is not using the bus, it takes in the ID number of another master device used in the bus acquisition operation by another master device, checks it with its own ID number, and if it matches, the master device (1) The bus is characterized in that the ID number of the slave device is changed by the changing means (14), and when there is a match in the ID numbers in the operation of the phase of selecting the other slave device, control is performed such that the own ID number is changed and selection is made. ID automatic identification method.