JPH08163017A - Vsat peripheral station equipment - Google Patents

Abstract

PURPOSE: To realize a VSAT(Very Small Satellite Communication Terrestrial Station) peripheral station in which frequency of down-loading is independently of the number of ports. CONSTITUTION: A program loader section 4 stores a port control program execution code part 35 down-loaded in the unit of protocol. The a port control program execution code part 35 stored in matching with the protocol in use is started to each of ports 5-8 as a port control task. In this case, a stack area is designated to a stack area of the port control task when the port control task is started to each of the ports 5-8, address information of a static data part of each of the ports 5-8 is informed to the port control task. Address information of the informed static data part is used for the port control task of each of the ports 5-8 and the individual static data part is designated in the unit of ports to execute the port control task. Thus, the memory capacity is reduced and the task start time is reduced.

Description

Detailed Description of the Invention

[0001]

The present invention is used in satellite communications. The present invention is used for VSAT (Very Small Aperture Terminal). In particular, it relates to a technique for simplifying program download from a central station to peripheral stations.

[0002]

2. Description of the Related Art The port control program in the peripheral station in the conventionally known VSAT is configured on a port-by-port basis. Is required for the number of ports held by.

For the conventional load function of the control program in the peripheral station via the satellite line, see "July 1988, N.
EC Technique, Vol. 41, No. 6, "JP-A-3-1985
No. 33 publication and Japanese Patent Application No. 5-322529. Although there is some difference in the port control program download control method between the central station and the peripheral stations, the number of times the port control program is downloaded by each peripheral station is the same for each peripheral station. It depends on the number of ports owned by.

Next, a conventional technique for downloading a port control program will be described with reference to FIGS. FIG. 5 is a block diagram of a peripheral station of a conventional VSAT. FIG. 6 is a block diagram of a conventional port control unit. In FIG. 5, the central station 1 holds a peripheral station 3 under its control via a communication satellite 2. Inside the peripheral station 3, a program loader unit 4 having a function of downloading and starting a port control program from the central station 1 and ports 5 to 5 are provided.
The port control units 9 to 12 for controlling the respective ports 8 are provided.

As shown in FIG. 6, port control units 9-12 are provided.
Is the program load area 20, stack area 21
And the program loaded into the program load area 20 is composed of an execution code section 22 and a static data section 23.

At the time of starting VSAT, only the program loader unit 4 is resident in the peripheral station 3, and no program exists in the port control units 9 to 12.
When the peripheral station 3 is activated, the program loader unit 4 loads the program load area 20 of each port control unit 9 to 12,
The execution code part 22 and the static data part 23 of the port control program are downloaded from the central station 1 via the communication satellite 2.

When the download is completed, the program loader unit 4 activates the port control program as a task. At this time, the stack area 21 is designated as the stack area of the task.

Even if the protocol used for each of the ports 5 to 8 is different, it is possible to perform independent processing for each port by changing the port control program downloaded to the port control units 9 to 12.

[0009]

In such a conventional configuration, the port control program is managed in units of ports. Therefore, even if the protocol of each port is the same and the content of the port control program used is the same, the same port control program is loaded in all the port control units.

This is because the structure of the port control program is a non-reentrant program in which the execution code part and the static data part are linked. In the case of a non-reentrant program, when a plurality of tasks execute one port control program at the same time, the static data part will be destroyed by the other tasks. Therefore, the port control program requires as many programs as the number of tasks even if the program contents are the same.

On the other hand, if a program having a reentrant structure is used, such a problem seems to be solved. However, since the port control program has a load module structure which can be executed independently, the linker can execute the execution code part and the static code part. The load module cannot be a reentrant structure because it is linked to the dynamic data part.

The execution code part and the static data part of the port control program are separately managed without being linked, and when the port control program is executed, the execution address of the execution code part and the address of the static data part are controlled separately. If it is an operating system with possible functions, it only recompiles a program written in a high-level language and re-entrants the program by separately calculating the execution code part and static data part when the program is executed. Can be used for
However, such a processing system requires a huge amount of memory.

For this reason, when the port control program has a load module structure that can be executed independently, it is necessary to manage each port even if it is the same program. The port control program execution code storage areas for the number of times and the number of ports are required.

The present invention has been made against such a background, and an object thereof is to provide a VSAT peripheral station in which the number of downloads does not depend on the number of ports. An object of the present invention is to provide a VSAT peripheral station that can reduce the amount of memory. An object of the present invention is to provide a VSAT peripheral station that can reduce task activation time.

[0015]

According to the present invention, a memory (40-43) is provided for each data input / output port (5-8), and this memory stores static data of a reentrant structure. The VSAT peripheral station device includes a static data section that stores the static data and a stack area that temporarily stores the static data.

A feature of the present invention is that a common memory (13) is provided commonly to the data input / output ports (5 to 8), and the common memory has a port having a reentrant structure. Port control program execution code section storage area for storing control program execution code section (35)
And a program loader unit (4) that downloads the port control program execution code unit via a satellite line, manages it in protocol units, and activates it as a task for each protocol.

It is preferable that the task includes means for indirectly referencing the static data part via a template.

Here, the template is a framework showing the relative position of the address of the static data part, and access to the static data part is referred to by the relative address from an arbitrary reference address. By writing the program so that the value of the reference template start address is stored in the stack area, the position of the static data part accessed from the program can be set by dynamically rewriting this start address value when the program is executed. Can be changed to

By using this method, the execution code part and the static data part of the port control processing part program can be separated and the program can be re-entered.

[0020]

Before the peripheral station is activated, only the program of the program loader section is resident in the peripheral station. When the peripheral station is activated, the program loader section stores the port control program execution code section downloaded from the central station in the port control program execution code section storage area for each protocol. For each port, the port control program execution code stored according to the protocol used is activated as a port control task. At this time,
A stack area is specified for each port in the stack area of the port control task. When the port control task is started for each port, the address information of the static data part of each port is notified to the port control task. The port control task of each port uses the notified address information of the static data portion to specify the individual static data portion for each port and execute the port control task.

In the processing system in which the port control program execution code part and the static data part are linked by the linker, a template is provided in the stack area for each port so that the static data part is indirectly referenced. However, by executing the port control program, independent values can be held for each port.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of an apparatus according to the present invention. FIG. 2 is a block diagram of the port control unit variable area.

The present invention is a data input / output port (5-8).
A memory (40 to 43) is provided for each, and this memory includes a static data part in which static data of the reentrant structure is stored and a VSAT peripheral area including a stack area for temporarily storing the static data. It is a station device.

Here, the feature of the present invention is that the common memory 1 is commonly used for the ports 5 to 8 for inputting / outputting data.
3, the common memory 13 is provided with a port control program execution code section storage area 35 in which a port control program execution code section of a reentrant structure is stored, and this port control program execution code section via a satellite line. A program loader unit 4 is provided for each protocol.

In FIG. 1, the central station 1 holds a peripheral station 3 under its control via a communication satellite 2. The peripheral station 3 has ports 5 to 8 as an interface with the ground line. Further, the peripheral station 3 internally has a program loader section 4 having a function of downloading the port control program execution code section from the central station 1 in protocol units and activating it as a task, and a port control protocol execution code section storage area in protocol units. 35, and port control unit variable areas 40 to 43 for each port.

FIG. 2 is a detailed diagram of the port control unit variable area.
4 and a stack area 45. Before the system is activated, only the program loader unit 4 is resident in the peripheral station 3, and no port control program execution code unit exists in the port control program execution code unit storage area 35.

The operation of the program loader unit 4 will be described with reference to FIG. FIG. 3 is a flowchart showing the operation of the program loader unit 4. When the peripheral station 3 is activated, the program loader section 4 downloads the port control program execution code section to the port control program execution code section storage area 35 from the central station 1 via the communication satellite 2. At this time, the download is performed in protocol units (S1).

When the download is completed, the program loader unit 4 activates the port control program execution code unit as the port control task 51 for each of the ports 5 to 8 according to the protocol used (S2). When a plurality of ports have the same protocol, the same port control protocol execution code part is designated. In the stack area of the port control task 51, the static data section 4 for each port
4 is designated (S3).

Port control task 5 for each port 5-8
1 is activated, the program loader unit 4 acquires the address information of the static data unit 44 of each port from the port control task 5
1 is notified (S4). When all the ports 5 to 8 have been notified (S5), the port control task 51 is executed using an individual static data area for each port (S).
6).

Next, the template will be described with reference to FIG. FIG. 4 is a diagram for explaining a procedure for making reentry possible by indirectly referring to the static data portion 44 using a template. The port control program execution code part storage area 35 is written in a high-level language using a compiler,
Port control program execution code part and static data part 44
In the processing system where and are linked by the linker,
Port control program execution code part and static data part 44
It shows how to separate and to make the program reentrant.

In FIG. 4, the port control task 51 rewrites the template start address 53 using the start address information of the static data section 44 notified from the program loader section 4. Since the template start address 53 itself is taken on the stack area 45, even if the port control program is executed by using the same port control program execution code part, an independent value can be held for each port.

Further, when the port control program execution code part is described, since all references to the static data part 44 are indirect references using the template 52 as described above, the static data part from the port control task 51 is used. Since 44 is accessed at a relative position from the template start address 53, independent processing can be performed for each of the ports 5 to 8 even if the program is executed using the same port control program execution code section. .

In this way, in the configuration of the port control processing of the peripheral station 3, the port control program execution code part and the static data part 44 can be separated and re-entered, and the peripheral station 3
In this case, the port control program execution code part is managed in protocol units, and the port control part variable area is managed in port units, whereby the number of times of downloading the port control program execution code part and the memory occupation amount can be minimized.

[0034]

As described above, according to the present invention,
VS that downloads do not depend on the number of ports
An AT peripheral station can be realized. According to the present invention,
A VSAT peripheral station capable of reducing the memory amount can be realized. According to the present invention, it is possible to realize a VSAT peripheral station that can reduce the task activation time.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a block configuration diagram of a port control unit variable area.

FIG. 3 is a flowchart showing the operation of a program loader unit.

FIG. 4 is a diagram for explaining a procedure of indirectly referring to a static data part using a template.

FIG. 5 is a block diagram of a conventional VSAT peripheral station.

FIG. 6 is a block configuration diagram of a conventional port control unit.

[Explanation of symbols]

 1 Central Station 2 Communication Satellite 3 Peripheral Station 4 Program Loader Section 5-8 Ports 9-12 Port Control Section 13 Common Memory 20 Program Load Area 21 Stack Area 22 Execution Code Section 23 Static Data Section 35 Port Control Program Execution Code Section Storage Area 40 to 43 Port control variable area 44 Static data section 45 Stack area 51 Port control task 52 Template 53 Template start address

Claims (2)

[Claims] 1. A memory (40-43) is provided for each data input / output port (5-8).
In a VSAT peripheral station device including a static data part in which static data having a reentrant structure is stored, and a stack area for temporarily storing this static data, the data input / output port is commonly (5-8) , A common memory (13) is provided, and a port control program execution code part storage area (35) in which a port control program execution code part having a reentrant structure is stored
And a program loader unit (4) which downloads the port control program execution code unit via a satellite line, manages it in protocol units, and activates it as a task for each protocol. . 2. The VSAT peripheral station apparatus according to claim 1, wherein the task includes means for indirectly referencing the static data section via a template.