JPH0310970B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

This invention relates to a termination method for backboard signal lines, and in a shelf unit that accommodates several to several dozen card units, a termination unit consisting of a terminating resistor is provided independently on the backboard that connects these cards. It is designed to be worn.

[Prior art]

Conventionally, termination circuits for backboard signal lines have been mounted on card units attached to both ends of the shelf. FIG. 1 shows a functional block diagram of a conventional common bus type information processing device. In the figure, 1 is a common bus that is an information exchange path between each unit, 2 and 2' are bus controllers that control the right to use the common bus, and this also includes the terminating resistor of the common bus signal line. . 3a to 3i are processor units that execute various information processing; 4a to 4K are common memories; 5a to 4K are common memories;
5j is an input/output control device, 6a to 6i are devices unique to each processor, and 7a to 7j are shared input/output devices. In Fig. 1, there is only one common bus, so for example, there are multiple processor units (3a to 3a).
3i) If these processors are trying to access the common memories 4a to 4K at the same time, they cannot access them at the same time. In such a case, the processor is forced to wait, but the bus controllers 2, 2' are in charge of this control, and the processor units 3a, 3i are kept waiting by the bus controllers 2, 2'.
common memory 4a via common bus 1 with permission from
-4k or shared input/output devices 7a-7j. In this configuration, when one of the processor units 3a to 3i fails, processing related to this processor unit cannot be executed, but the remaining healthy processor units can continue processing. This is not limited to the processor units 3a to 3i, but also includes the bus controllers 2, 2', common memories 4a to 4k, input/output control devices 5a to 5j, and shared input/output device 7a.
The same applies to the case of ~7j. Furthermore, it has been realized that a faulty unit, except for the bus controllers 2 and 2', can be replaced with a good unit online without interfering with the operation of other units.

[Problem to be solved by the invention]

However, although two sets of bus controllers 2 and 2' are prepared, it was possible to replace them with good quality bus controllers online without interfering with the operation of other units. This is because the bus controller is equipped with a terminating resistor, so if it is removed from the backboard, the electrical termination of the backboard signal line will be destroyed, making it impossible to achieve normal data transmission. In order to avoid this, it is possible to insert a terminating card unit in which only a terminating resistor is attached to a standard card unit at both ends of the backboard, but this increases the cost and reduces the number of cards that can be stored in the standard card unit. It was hot. In consideration of these points, the present invention enables on-line insertion and removal of the bus controller unit by separating the terminal unit from the bus controller unit without reducing the number of standard card units stored.

[Means to solve the problem]

In this invention, focusing on the fact that the termination unit can be made extremely small by using a collective resistor or a thick film IC, the termination unit consisting of a termination resistor is configured independent of the card unit, and this termination unit is connected to the backboard signal line. Both ends of the card unit are installed from the opposite side to realize the termination of the backboard signal line.

[Effect]

Since a termination unit is installed, when replacing a card unit, the electrical termination of the backboard signal line will not be destroyed, and the operation of other card units will not be affected. In addition, since the termination unit itself is composed of a termination resistor that has a very low possibility of failure, it is almost impossible to replace the termination unit due to failure and destroy the electrical termination of the backboard signal line.

Embodiment FIG. 2 shows an embodiment of the present invention, and is a front view of the back board 8 viewed from the connector pin side, that is, the side opposite to the card unit insertion side. Usually, a motherboard is attached that connects these connectors. Here, a termination unit 10 is directly attached to the backboard 8 outside the connectors 9 at both ends to realize the termination of the backboard signal line. FIG. 3 also shows circuit diagrams of two different types of termination units. Figure a shows a double-hung type, with one end of the resistor 10a connected to the power supply _Vcc , and one end of the wire resistor 10b grounded. Further, a connection point between these resistors 10a and 10b is connected to a backboard signal line. Figure b shows a single-hanging type, and one end of the resistor 10c is connected to the power supply.
It is connected to _Vcc , and the other end is connected to the backboard signal line. Thus, as a terminating unit, terminating resistors of the type shown in FIG. There is also. Similar to FIG. 2, FIG. 4 is a front view of the backboard viewed from the connector pin side, that is, the side opposite to the insertion side of the standard card unit. In this case, the conductor pattern group 11 is formed as shown in the figure as an example, and in addition to each connector 9, a termination unit 10 is formed.
are attached to connectors at both ends of the backboard 8. Note that the termination unit 10 can also be made removable. Further, FIG. 5 shows a configuration diagram of the termination unit 10. In the figure, 13 indicates a connector or a printed circuit board that can be fitted to a connector pin, and 14 indicates a terminating resistor.
Appropriate connections are made between the group and the connector 13. FIG. 6 shows a functional block diagram of an information processing apparatus according to the present invention corresponding to the conventional example shown in FIG. , 10' is a terminal unit,
12 and 12' are bus controllers 2 and 12' shown in FIG.
2' is a bus controller with a terminal unit separated from it; 3a to 3i are processor units; 4a to 3i are processor units;
4k is a common memory, 5a to 5j are input/output control devices, 6a to 6i are devices unique to each processor,
7a to 7j are shared input/output devices. Therefore, in the configuration shown in FIG. 6, unlike the case where the bus controllers 2 and 2' shown in FIG. 10,
10' can be inserted and removed, so the electrical termination will not be destroyed, and therefore the signal will not be disturbed and normal transmission will not be possible.

【Effect of the invention】

As described above, according to the present invention, since the terminating unit is constructed from a material other than a standard card unit, it is possible to avoid installing a terminating resistor in the bus controller, and in the event of a failure of the bus controller, this can be replaced with a terminating resistor.
If a set is prepared, it is possible to replace the bus controller with a good one online without interfering with the operation of other information processing units. Furthermore, since the termination unit is configured to be mounted on the backboard, there is no need for a termination card unit in which only a termination resistor is attached to a standard card unit, and therefore there is no need to reduce the number of inserted card units. Further, in the present invention, since the bus controller does not have a termination function, the bus controller can be mounted at any position on the backboard, which is very effective in improving data transfer speed. In other words, in the case of the parallel bus priority processing method, each processor unit requests the right to use the bus, and permission to use the bus is issued according to the priority of each processor unit. is at the center compared to one end of the backboard, the signal propagation time is 5lns (=5ns/m×l/2×2) where l: backboard signal line length (unit: m) 5ns : This is because the signal propagation time per unit signal line length can be shortened. In summary, the gist of this invention is:
When realizing the backboard termination of the shelf that houses the card unit, the card This system allows card units such as processors, common memory, and bus controllers to be inserted and removed online without destroying the electrical terminations of the backboard signal lines without reducing the number of units inserted. It can be widely used as a termination method for unit common bus type information processing devices.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of a conventional common bus type information processing device, FIG. 2 is a front view of a back board 8 viewed from the connector pin side, and FIG. The circuit connection diagram of FIG. 4 is another embodiment according to the present invention,
5 is a configuration diagram of a termination unit, and FIG. 6 is a functional block diagram of a common bus type information processing apparatus according to an embodiment of the present invention corresponding to FIG. 1. . 1... Common bus, 3a to 3i... Processor unit, 8... Back board, 9... Connector,
10, 10'...terminal unit, 10a, 10b,
10c...Terminal resistor, 12, 12'...Bus controller.

Claims (1)

[Claims] 1. In a backboard-based common bus type information processing device in which each unit such as a processor, a common memory, a bus controller, etc. is mounted on a backboard as a card unit, a terminating unit consisting of a terminating resistor is configured independently of the card unit, A method for terminating a backboard signal line, characterized in that the terminating unit is attached to both ends of the backboard signal line from the side opposite to the card unit to realize the termination of the backboard signal line.