JP3512146B2 - Device driver device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a desktop personal computer having various external devices, a notebook personal computer, an in-vehicle terminal or the like, and an optional expansion bus (10base-T or high-speed in-vehicle L).
The present invention relates to a device driver device for transmitting / receiving data between an external device and a device connected via an AN or the like.

[0002]

2. Description of the Related Art In the design and development of in-vehicle terminal hardware, in order to perform bidirectional communication between an in-vehicle terminal and an external device, a communication driver is created in accordance with each connection form and the accompanying communication protocol. is doing.

The communication driver created according to the connection form and the communication protocol, for example, when the I / F of the bus is changed due to an increase in the amount of data transmission, the communication driver is recreated from 1 according to the change. . Also, while various interrupts occur during application processing, a device driver built with a specific interrupt number must generate an interrupt even if it is connected to hardware that does not allow assignment of the same interrupt number. I couldn't.

[0004]

As described above, in the related art, there are a plurality of versions of the transmission / reception device driver simply because the buses of the connection forms are different. There was a problem that a lot of maintenance man-hours had to be applied.

The present invention has been made in view of the above circumstances, and automatically absorbs a difference in hardware environment such as a connection form and a communication protocol to easily perform bidirectional communication between a plurality of devices. It is an object of the present invention to provide a device driver device that enables the above.

[0006]

The present invention has taken the following means in order to solve the above problems.

[0007]

[0008]

[0009]

[0010]

The invention according to claim 1 connects to a device.
An interrupt to the application section of the external device
DMA ( Direct
memory access ) D to perform data transfer by transfer
And a MA function, the detecting the interrupt number vacant from registered interrupt number table of the interrupt number used by an application installed in an external device, the external device by detecting empty interrupt number was It is configured to be registered as an interrupt number for transmission and reception used for two-way communication with.

With this configuration, the interrupt number can be switched arbitrarily.
The state that other external devices are connected is
It can be used universally without changing,
In addition, the minimum unit of DMA transfer must meet the memory limit of the external device.
By doing so, high-speed
Directional communication becomes possible. In addition, bidirectional communication can be performed by a plurality of units without depending on the manufacturer of the connected hardware and other external devices.

[0013]

[0014]

The invention according to claim 2 is connected to a device.
An interrupt to the application section of the external device
DMA ( Direct
memory access ) D to perform data transfer by transfer
An MA having a MA function is used to extract memory capacity limit information from a memory management unit used by the operating system mounted on the external device to manage a memory area, and one block per block at the time of DMA transfer is extracted from the extracted limit information. Adopt a configuration that calculates the data transfer amount.

With this configuration, the interrupt number can be switched arbitrarily.
The state that other external devices are connected is
It can be used universally without changing,
In addition, the minimum unit of DMA transfer must meet the memory limit of the external device.
By doing so, high-speed
Directional communication becomes possible. Also, the memory will be carried out at up to 64 K bytes in the execution environment. Therefore, it means that it can be used in a standard form without adding memory to the connected machine, and that there are no restrictions on various OSs. For example, the data securing exceeding 64 K bytes in MS-DOS can not. Therefore, for data transfer exceeding 64 Kbytes, the application had to devise a process such that 64 Kbytes were one unit. As a result, the transfer time of communication has been increased in the case of large-scale data. In addition, there is a problem that the maximum memory reservation amount as a system must be examined for each system. However, according to the present invention, the DMA is automatically
The application enables communication without dividing the data in order to calculate the minimum unit at the time of transfer.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a functional block diagram of an embodiment according to the present invention. This embodiment has the same functions (hardware and software) as a personal computer.
It is an example of a communication driver device for performing bidirectional communication between a vehicle-mounted terminal having a terminal and a device connected to the vehicle-mounted terminal by various buses (10base-T, high-speed vehicle-mounted LAN, etc.).

The communication driver device 1 is a communication driver for performing bidirectional communication between an in-vehicle terminal which is an external device and a device 2 connected in a predetermined connection form. Data is given from the communication instruction unit 3 or data from the device 2 is notified to the bidirectional communication instruction unit 3.

The communication driver device 1 includes an initialization unit 1
1, bidirectional communication unit 12, transmission / reception data memory 13, message disassembly / conversion / assembly unit 14, frame transmission / reception unit 1
5, a DMA 16 on the main side, a transmission interrupt notification unit 17, and a reception interrupt notification unit 18.

The initialization section 11 is a section which executes initialization processing independently of an application when the system is started up. For initialization of communication protocol selection, automatic allocation of interrupt numbers and DMA transfer. Contains the initialization memory area calculation (max memory area).

The bidirectional communication section 12 includes a bidirectional communication instruction section 3
This is a part that discriminates the data type instructed from the (bidirectional application part of the external connection device) and distributes it to small-scale data, large-scale data, and broadcast data.
The bidirectional communication unit 12 includes RS232C, TCP / IP,
It is possible to support a plurality of communication protocols such as a high-speed in-vehicle LAN, and the communication environment is prepared according to the setting contents of the protocol format setting file 19 described later.

The transmission / reception data memory 13 is an area for storing transmission data and reception data such as small-scale data, large-scale data, group broadcast and simultaneous broadcast. In the default state, the small-scale data has a data length of 16 bytes or less, but the user can change the data length by describing it in the setting file. In the case of small-scale data, the effect obtained by using the DMA is not so great, so the data is transferred by a bus (serial / parallel) system. Large-scale data means a data length exceeding 16 bytes in the default state.
In the case of large-scale data, the data is divided / assembled into the minimum unit determined by one block, and bidirectional data communication is performed between the connection devices by DMA transfer. The group broadcast and broadcast data is for broadcasting the same information to all connected devices in group units or all at once, based on the contents described in the setting file.

The message disassembling / converting / assembling unit 14 interprets and converts the request data and the received data from the application into a form that can be recognized by each device according to the setting contents of the protocol format setting file 19. is there.

The frame transmission / reception section 15 is a section for transmitting / receiving a frame in accordance with the contents of the protocol setting format file 19.

The master side DMA 16 is a part constituting a DMA (Direct memory access) function of an externally connected external device, and the master side DMA 16 and the slave side DMA 16 are provided.
Data is bidirectionally exchanged with the device 21 through the communication cable.

The transmission interrupt notifying section 17 is for notifying the application side from the device driver side that the transmission of the application is completed, and the reception interrupt notifying section 1
Reference numeral 8 is a part for informing the application that the device driver has received the data. The transmission interrupt notifying unit 17 and the reception interrupt notifying unit 18 use the interrupt numbers automatically set by the initialization unit 11 to generate an interrupt.

Protocol format setting file 19
Describes how to connect to an external device, including serial, parallel, TCP / IP, and high-speed in-vehicle LA.
It describes basic communication conditions such as N. The device driver side performs initialization and data transmission / reception while referring to the setting contents of the protocol format setting file 19.

FIG. 2 shows a setting example of the protocol format setting file 19.

Protocol format setting file 19
Is a setting file for describing the communication protocol for communication and is prepared by the user. In the protocol format setting file 19, [communication procedure],
[Communication speed] [Data length] [Parity] [Stop bit] [CR, CR / LF conversion] [Port] [Flow control] [OS] etc. are set. For example, the user selects a communication procedure corresponding to the connection form from [communication procedure].
FIG. 2 illustrates an example in which a high-speed vehicle LAN is selected from [Communication Procedure]. In addition, the user sets the communication speed, the presence / absence of parity, and the like. The description starting with “;” in each setting is invalid. In the case of TCP / IP and high-speed in-vehicle LAN, the communication speed is specified by the communication speed set on the LAN board to be connected.
The description after [Communication speed] is invalid. The items that describe the operating system are MS-DOS, WIN
Set the OS name such as DOWS95 (registered trademark of Microsoft Corporation).

The device 2 is a line (wired or wireless) using the device driver apparatus 1 and various communication protocols.
It is assumed that the device is connected by the device driver side (external device), and the slave side DM is a receiving port when the DMA transfer is performed.
Equipped with A21.

The bidirectional communication instructing section 3 is an application section for controlling bidirectional communication of information with an external device connected to the outside, and includes simultaneous broadcast communication and the like. The interrupt handler table 31 in which the state of the interrupt number is registered on the OS of the external device, the memory manager 32 for managing the memory information, and the like are supported.

Next, FIG. 3 shows how the device driver of this embodiment detects a vacant interrupt number. In the device driver device 1, the initialization unit 11 reads the interrupt handler table 31 supported by the OS of the external device when the system is first started up. In the interrupt handler table 31, it is possible to know which interrupt number is used and which interrupt number is not used. Therefore, the initialization unit 11 refers to the interrupt handler table 31 to check whether each interrupt number is free (step S1). Figure 3
In the example shown in, the interrupt numbers 1 and 4 are in an empty state.

Next, a vacant interrupt number is searched, two small numbers are selected and registered in the interrupt table 31 (step S2). Then, the setting of the function vector for the interrupt number is forcibly written to the position corresponding to the interrupt number (step S3). The function vector corresponding to the interrupt number 1 indicates the vector address of the reception processing unit of the system, and the function vector corresponding to the interrupt number 4 indicates the vector address of the transmission processing unit of the system. As a result, when data is transmitted / received, a specific interrupt is notified to the device driver side.

As described above, two free interrupt numbers are detected from the interrupt handler table 31 and given two arbitrary interrupt numbers for transmission and reception, thereby connecting the connected hardware. It becomes possible to perform two-way communication between a plurality of devices without depending on the manufacturer and external device.

Next, a minimum packet setting method for transferring data using DMA will be described with reference to FIG.

The initialization unit 11 of the communication driver device 1 calls a memory information acquisition function corresponding to the OS on which the system is operating when the system is started up. WINDOWS
Taking the case of 95 as an example, Global Memory Status is called (step T1). The memory information is read from the memory manager 32 supported by the OS of the external device using the memory information acquisition function.

The memory information structure 50 shown in FIG. 5 is prepared, and the corresponding value of the memory information read from the system is substituted into each part (size per unit, usable physical memory size, etc.) of the memory information structure 50. (Step T2).

By referring to the contents of the memory information structure 50 in which the memory information is set, 1 in the DMA corresponding to the system is set.
The packet size per frame is calculated (step T3). Further, it is determined from the value stored in the usable physical memory size of the memory information structure 50 whether the total memory size exceeds a predetermined value (step T4). Here, the MS-DOS set in the [OS] of the protocol format setting file 19 is 6
Since the data exceeding 4 kbytes cannot be secured, 6
4 kbytes are used as the predetermined value.

If the memory size does not exceed 64 Kbytes, the DM is divided so that it can be divided into a minimum of 8 frames.
The minimum unit of A transfer is determined (step T5). on the other hand,
If the memory size exceeds 64K bytes,
The usable physical size is calculated so that the page frame is divided into 256 units, and the minimum unit of DMA transfer per unit is determined (step T6). Then, a generally vacant address is found as a DMA memory address from the memory information of the memory manager 32, and the minimum unit and the memory start address are recognized by the bidirectional communication unit 12 of the communication driver device 1 (step T7).

As described above, when the system is started up, the minimum unit of the DMA transfer is determined according to the use of the system of the external device and is instructed to the necessary place including the bidirectional communication section 12.

In the communication driver device 1 which has been initialized as described above, when the bidirectional communication instructing section 3 instructs the data transmission, the bidirectional communication section 12 determines the data type and the small-scale data is sent. , Large-scale data, or broadcast data.

In the case of small-scale data, an identifier indicating that the data is small-scale data is attached to the header and stored in the transmission / reception data memory 13.

When the message assembling / converting / disassembling unit 14 detects that the transmission data is stored in the transmission / reception data memory 13, the protocol format setting file 1
The request data from the application is converted so as to be recognized by the device 2 in accordance with the setting of 9.

The data converted by the message assembling / converting / disassembling unit 14 is frame-assembled by the frame transmitting / receiving unit 15 according to the setting of the protocol format setting file 19 and transmitted to the device 2 without using DMA.

Further, when the bidirectional communication unit 12 judges a large-scale data, since the DMA transfer is performed, the data is divided into the minimum units calculated in the above-mentioned initial setting and stored in the transmission / reception data memory 13. Frame transmitter / receiver 1
In 5, when the large-scale data identifier is set in the header, the master DMA 16 is used to directly transfer data to the slave DMA 21 of the slave device 2. The frame configuration at this time uses a template of the frame created according to the setting contents of the protocol format setting file 19 at the time of initial setting.

When the transmission is completed, the frame transmitting / receiving unit 15
The transmission interrupt notifying unit 17 which has received the notification of the transmission completion from the above notifies the bidirectional communication instructing unit 3 of the transmission completion notification by using the transmission interrupt number acquired in the above-described initial setting.

On the other hand, from the device 2 to the communication driver device 1
When data is input to the external device, the request data received by the frame transmitting / receiving unit 15 is notified to the reception interrupt notifying unit 18. The reception interrupt notification unit 18 sends a reception request notification to the bidirectional communication instructing unit 3 using the reception interrupt number acquired in the initial setting.

When the communication driver unit 1 issues a reception permission to the device, for example, the DMA 16 on the main side is transferred by DMA transfer.
Data is transferred to. When the frame transmitting / receiving unit 15 transfers the message part to the message assembling / converting / disassembling unit 14, the message assembling / converting / disassembling unit 14 converts the data in a form suitable for the setting of the protocol format setting file 19 so that the external device can read the data. The data is stored in the transmission / reception data memory 13.

When the received data is written in the transmission / reception data memory 13, the bidirectional communication section 12 sorts the received data into small-scale data and large-scale data. The received data is transferred to the bidirectional communication instructing unit 3 using the minimum unit according to the data type calculated when the system is started up.

As described above, in this embodiment, the user describes the protocol format setting file 19 so that RS232C serial communication, parallel communication, and T232C communication can be performed.
Regardless of the form of communication such as CP / IP and high-speed in-vehicle LAN communication, the communication driver device 1 side assembles a frame in a suitable form, and automatically creates an interrupt number for transmission and reception and an empty memory area. And the bidirectional communication of data using DMA and interrupt is performed. Therefore, even if the system configuration of the hardware connected to the system is different, for example, bidirectional communication is possible even in an environment where there are different interrupt numbers and memory states, and the communication procedure is RS232C serial. communication,
Regardless of the form of communication such as parallel communication, TCP / IP, high-speed in-vehicle LAN communication, it is common to realize bi-directional or simultaneous broadcast communication between multiple units at high speed by using DMA and interrupt. It is possible. The user only has to write the setting file, and since the communication is realized at the device driver level, the development man-hours and maintenance man-hours can be reduced, and the efficiency of system development can be improved. .

[0052]

As described above in detail, according to the present invention, the difference in the hardware environment such as the connection form and the communication protocol is automatically absorbed to easily enable the bidirectional communication between a plurality of devices. A device driver device can be provided.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a communication driver device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a description example of a protocol format setting file in the above embodiment.

FIG. 3 is a flow chart for realizing an interrupt detecting means in the above-described embodiment.

FIG. 4 is a flow chart for performing DMA memory setting according to the embodiment.

FIG. 5 is a configuration diagram of a memory information structure according to the above embodiment.

[Explanation of symbols]

1 Communication driver device 2 devices 3 two-way communication instruction unit 11 Initialization section 12 Two-way communication unit 13 Transmission / reception data memory 14 Message disassembly / conversion / assembly department 15 frame transceiver 16 Master DMA 17 Send interrupt notification section 18 Reception interrupt notification section 19 Protocol format setting file 31 Interrupt handler table 32 memory manager

Claims (2)

(57) [Claims] 1. An interrupt function for interrupting an application section of an external device connected to a device, and a DMA function for executing data transfer by DMA (Direct memory access) transfer with the device , The above
The ratio used by the application installed in the external device
Free numbers from the registered interrupt number table
Detecting the incoming number and using the detected vacant interrupt number as the external device
Interrupt number for sending and receiving used for two-way communication with
A device driver device characterized by being registered as . 2. An application of an external device connected to the device
Interrupt function to insert an interrupt to the application
DMA ( Direct memory access ) transfer
When a DMA transfer is performed, the memory capacity limit information is extracted from the memory management unit used by the operating system installed in the external device to manage the memory area. A device driver device for calculating the amount of data transfer per block of