JPH0916499A - Communication controller - Google Patents

Abstract

PURPOSE: To protect data without lowering performance and to easily explicate the cause when a fault is generated relation to a communication controller provided with a communication protocol driven by a real time OS. CONSTITUTION: A memory area is divided into an OS management area and a user area, the transactions of the respective areas are mapped one to one, a user can access only the user area and the OS can access both areas. The abnormality detection of the transaction desired to be released by the user is performed based on the mapping information of the OS management area.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control device, and more particularly to a communication control device having a communication protocol driven by a real-time OS.

The communication control unit is equipped with a smaller firmware than software, and is used as a general purpose O
Since the overhead of using S is too large, it is necessary to develop and use a dedicated OS by itself.

[0002]

2. Description of the Related Art In a conventional communication control device using such a dedicated OS, the memory area managed by the OS is the same as the memory area accessed by a user (task or application).

Therefore, when the user needs a transaction managed by the OS, a hunt request is made to the OS, and the OS allocates the transaction under the control to the user.

The user uses the assigned transaction to execute processing such as transferring user data and a message to another user via a mailbox.

When such processing is completed, the user notifies the OS of a request for releasing the hunted transaction, and the OS brings the transaction into the released state.

[0006]

However, in the OS system in such a communication control device, when one user hunts a certain transaction and then releases the transaction, another user gives a command to the OS. If you do double release for a transaction that was previously released due to an address error etc. even though you hunted and released another transaction,
The transaction released first by the OS is overwritten by the transaction released next, resulting in data destruction.

Further, in the transaction assigned by the OS, if an address error occurs in the data processing, abnormal writing occurs,
Even in such a case, data destruction will occur.

As a result, there is a problem that the firmware runs out of control and it is very difficult to elucidate the cause even though it is known that the data is abnormal even if the data collected after the failure is analyzed.

From such a point of view, there is a system in which a protect mode is introduced into the communication control device in order to improve the processing capability, expand the memory and support the function. However, although the processor speed is improved, the protect mode by the protect mode is improved. There is a problem in that the performance is lowered by the realization, and the effect is not as high as that of the improved processor.

Therefore, it is an object of the present invention to provide a communication control device capable of protecting data without degrading performance and easily clarifying the cause when a failure occurs.

[0011]

[Means and Actions for Solving the Problems] The main processing of the communication control device is to handle a message,
Messages can range from a few bytes to hundreds of bytes,
The long message is the one that works, so we have optimized such inter-task communication.

In the inter-task communication of a long message, it was not necessary to hunt the inter-task communication transaction if the OS information was stored in the user data transaction.
The involvement of S is a protection exception.

The transaction itself may be controlled by classifying it into an OS area and a user area, but it is unrealistic because the number of transactions is huge.

Therefore, in the present invention, as conceptually shown in FIG. 1, the memory area ME is divided into an OS management area A and a user area B.

Then, the user sets only the user area B to be accessible, and the OS sets both areas A and B to be accessible.

By setting the memory area ME in this manner, the OS allocates, for example, the transaction B1 under its control to the user's hunt request, and the transaction B1 to the user.

At this time, the OS maps the allocation result in the OS management area A.

When the user performs a predetermined process after the transaction B1 is allocated, the user requests the OS to release the transaction B1.

In this way, the OS that receives the release request sends the address of the transaction B1 and the like to the OS management area A.
The abnormality can be detected by referring to the mapping information of.

That is, for example, transaction B1
If the address is the address of the OS management area A or the address of another memory area, it can be detected as a transaction release address error.

Further, the OS uses the same address as the address when the transaction B1 is released.
When another user requests to release a transaction with respect to the same address as this transaction B1, it is possible to detect an abnormality as a double release state.

Furthermore, when a transaction is transferred by a mailbox in the user area, if a transaction release request is issued, it can be detected as an abnormal state.

Further, the OS can monitor the abnormal time of the transaction assigned to the user, and if the abnormal time exceeds a predetermined time, it can detect that it is in an abnormal state.

Further, when the OS accesses the prohibited OS management area A, the OS can detect this as an abnormality.

[0025]

FIG. 2 shows an embodiment of a memory map of a memory area ME used in a communication control device according to the present invention. In this embodiment, as shown in FIG. It is divided into an area A and a user area B, and in the OS management area A, an OS transaction area TE, an OS management table MT and an OS.
It is divided into a buffer area (not shown), and a user area B is further divided into a user transaction area U.
It is divided into a TE, a user management table UMT, and a user buffer area UBE.

Further, in the user transaction area UTE in the user area B, the semaphore link area storing the address of the next transaction area combined with the semaphore counter area 1 storing the start address of each transaction area. 2, a busy threshold area 3, a message size area 4, a free management table area 5 in which the next free management table address is stored, and a management table pointer area 6 in which the start address of the next free management table is stored. It is composed of.

Further, the user management table UMT stores a link area 7 in which the address of the next link is stored, a pointer area 8 in which the head address of the user buffer area UBE is stored, and a message (mail) stored message. The user buffer area UBE further comprises an I-link area 10 indicating the start address of the message and a C-link area 11 indicating the address of the next message.

User transaction area UTE and user management table U in user area B
MT and user buffer area UBE are UTE
1: UMT1: UBE1, UTE2: UMT2: UBE
2, UTE3: UMT3: UBE3, and since the OS constantly maps the memory information of the user area B in a one-to-one correspondence with the OS management area A, these are TE1: MT1, TE2. : MT
2, TE3: MT3, which corresponds to the OS management area.

The operation of the communication control device according to the present invention using such a memory map will be described below with reference to FIGS.

First, the user 21 requests the OS to hunt a transaction for sending the processed data to another user 23. At this time, the user 21 wants to use the number of transactions (“1” in this embodiment).
Is also requested.

Since the OS that has received such a request from the user 21 has only one transaction requested by the user 21, there is no transaction in the idle chain IC composed of the FIFO memory provided in the OS.
Areas UTE1, 2, 3, ... UTEn are set in this order, and the transaction (transaction area UTE1 in this example) set on the exit side of the idle chain IC is assigned.

At this time, the transaction area UT
E1 is pushed out from the idle chain IC, and the subsequent transaction areas UTE2, 3, ...
UTEn is sent to the exit side one by one.

Here, the user 21 wants to send the processed data to another user 23 in order to send a transaction.
Since the area UTE1 has been allocated, the user 21 transfers the processed data to the user 23 via the mailbox 24 by this transaction area UTE1.

When the user 21 releases the transaction area UTE1 after finishing the data processing in this way, the user 21 notifies the OS of the release request.

As a result, the OS sets the previously hunted transaction area UTE1 at the entrance side of the idle chain IC to be managed.

On the other hand, when the user 22 needs two transactions and notifies the OS to that effect, the OS
Refers to the idle chain IC and currently has transaction areas UTE2 and UT sequentially located from the exit side.
Assign E3.

In this way, the user 22 processes the data using the assigned transaction areas UTE2 and UTE3. In this case, the user 22
Performs predetermined processing using the message 9 in the user management table UMT indicated by the management table pointer 6 of the allocated transaction areas UTE2 and UTE3. The message 9 in this case is the I-link 10 in the user buffer area UBE.
And are processed according to the connection relationship by the C-link 11.

When the user 22 performs the predetermined processing and releases the two allocated transaction areas UTE2 and UTE3, the OS which has received this notification makes a transaction to the entrance side in the idle chain IC as described above. -Set areas UTE2 and UTE3.

In this way, the OS in the communication control device 20
The detection of an abnormal condition that may occur when a user hunts and releases a transaction is described below.

(1) Abnormal release address When the user 21 releases the already allocated transaction area UTE1 as described above,
The OS is the previously assigned transaction area UT in the OS management area TE and the OS management table MT in the OS management area A shown in FIG.
Since the E1 address is mapped, user 2
Transaction area UTE requested to be released by 1
The address 1 and the address stored in the OS management area A are compared, and if they do not match, it can be determined that there is an abnormality.

If there is such an abnormality, the protect mode is entered.

(2) Double release error Now, the user 21 is in the transaction area UTE1.
Correctly release the transaction area UTE to the entrance side of the idle chain IC in the OS.
1 is set, but after this, the transaction areas UTE2 and UTE3 to which the user 22 is assigned are set.
When an attempt is made to release the transaction area UTE1 that has become the same as the transaction address released by the user 21 due to an address error for some reason, the OS manages the transaction area already allocated by the user 22 in the OS management area A managed by the OS.
Since the area is known by the OS transaction area TE and the OS management table MT, such double release can be detected.

(3) Releasing during mailbox linking FIG. 4 shows a state in which the mail boxes are linked. In this example, the user 21 is assigned four transaction areas UTE by the OS. In this case, the user 21 transfers the message from the mailbox 24 to the user 23 by using the four transaction areas UTE as described above, but the user also uses the four transaction areas in the mailbox 24. The link with 23 is made.

FIG. 4 shows a relation in which the messages MG1 to MG4 in the user management table UMT corresponding to these transaction areas UTE are linked, but the messages MG1 to MG4 transferred in the mailbox 24 are constantly OS. Monitors the I-link 10 indicating the start address of the message and the C-link 11 indicating the connection relation of the message by the user buffer area UBE.

If the user 21 erroneously requests the OS to release the message when the mailbox 24 transfers the intermediate message MG3, the OS constantly keeps the I-links 10 and C by the user buffer area UBE. -Because the link 11 is monitored, it is possible to know that the fourth message MG4 is not processed, and it is possible to detect such a release in the mailbox link as an abnormality.

However, the OS does not actually detect the abnormality by the I-link 10 and the C-link 11, but
The abnormality is detected by referring to the link 7 in the user management table UMT.

FIG. 5 shows the flow of abnormality detection in such a mailbox link.
When the user sends a message, a predetermined flag is turned on and the message MSG is received by the user 23, and the flag is set to be OF as if the link is released.
Change to F.

However, the flag is ON as described above.
When the transaction is released in the mailbox link that is, the error is detected and this error information is stored in the error storage area ER.

(4) Abnormality detection of long-term use When the OS allocates the transaction area UTE as described above, it starts a timer, and when this timer continues for a predetermined time or more, that is, the transaction When the use is continued more than necessary, it can be detected as an abnormal use state.

(5) Detection of Abnormal Address The OS constantly monitors the writing and reading of the memory area ME as described above, and when the user side accesses the OS management area A side, this is sent to the protect side. Abnormality is detected as an access.

[0051]

As described above, according to the communication control device of the present invention, the memory area is divided into the OS management area and the user area, and the transaction of each area is mapped in a one-to-one manner. Only the area can be accessed and the OS can access both areas, and the abnormality of the transaction that the user wants to release is detected based on the mapping information of the OS management area. It is possible to detect the release in the mailbox link, the detection of the long-term use status, and the access to the abnormal address.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the concept of a communication control device according to the present invention.

FIG. 2 is a map diagram of a memory area in the communication control device according to the present invention.

FIG. 3 is a block diagram for explaining the operation of the communication control device according to the present invention using the memory map shown in FIG.

FIG. 4 is a diagram for explaining an operation when releasing a transaction during mailbox linking in the communication control device according to the present invention.

5 is a time chart showing an operation of abnormally releasing the transaction shown in FIG.

[Explanation of symbols]

 ME memory area A OS management area B user area UTE user transaction area UMT user management table UBE user buffer area TE OS transaction area MT OS management table IC idle chain 20 communication controller 21-23 users (tasks) 24 Mailbox In the figure, the same reference numerals indicate the same or corresponding parts.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G06F 12/02 540 G06F 12/02 540

Claims (6)

[Claims] 1. A memory area is divided into an OS management area and a user area, and transactions in each area are mapped one-to-one so that a user can access only that user area and an OS can access both areas. At the same time, the communication control device is characterized in that a transaction in the user area that the user wants to hunt is assigned, and the abnormality of the transaction that the user wants to release is detected based on the mapping information of the OS management area. 2. The communication control device according to claim 1, wherein the abnormality detection is release address abnormality detection of the transaction. 3. The communication control device according to claim 1, wherein the abnormality detection is double release detection of the transaction. 4. The communication control apparatus according to claim 1, wherein the abnormality detection is release detection of a transaction during linking of a mailbox used for transfer of a transaction in the user area. 5. The communication control device according to claim 1, wherein the OS detects an abnormal time use state of a transaction assigned to the user. 6. The communication control device according to claim 1, wherein the OS detects a user's access to the OS management area as an abnormal state.