JP3670128B2 - Navigation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-vehicle navigation device that implements a plurality of models having different price ranges or destinations by mounting the same execution program on hardware having the same basic specifications.
[0002]
[Prior art]
Navigation devices that detect the current position of a vehicle using a GPS signal sent from a GPS (Global Positioning System) satellite have already been put into practical use and are widely used. The in-vehicle navigation device is connected to an in-vehicle audio device, a TV tuner, and the like, and is also used as an operation unit and a display unit of these devices.
[0003]
By the way, depending on the price range, destination, etc., the navigation device develops a plurality of models having the same basic specifications but different display screens and additional functions (for example, whether or not an air conditioner is displayed). There is a need. In this case, conventionally, as shown in FIG. 7, different execution programs (software) A, B, and C are mounted for each model on hardware A1, A2, and A3 having the same basic specifications. .
[0004]
In many on-vehicle navigation devices, an execution program is stored in a rewritable storage device such as a flash memory so that the program can be upgraded. The version upgrade program is supplied, for example, recorded on a CD-ROM together with the latest map data.
[0005]
[Problems to be solved by the invention]
Since the conventional navigation apparatus requires different execution programs for each model, it is necessary to create a CD-ROM for each model when upgrading the version, which increases the cost of creating the CD-ROM. In addition, the manufacturer also needs to manage software for each model, which is complicated.
[0006]
As described above, an object of the present invention is to provide a navigation apparatus that can operate each model with the same execution program for models having the same basic hardware specifications.
[0007]
[Means for Solving the Problems]
In the navigation device that detects the position of a vehicle by a signal from a GPS satellite and displays a map image around the vehicle on a display, the above-described problem is a model identification data generating unit that generates model identification data, and a plurality of models. An execution program storage means for storing an execution program composed of a common main program and a plurality of model-specific subprograms, a processing means for executing processing according to the execution program stored in the execution program storage means, and a nonvolatile memory And a random access memory, and the processing means copies the model identification data generated by the model identification data generation means to the nonvolatile memory, and further copies the model identification data to the nonvolatile memory. Copy the model identification data to the dynamic random access memory Navigation, characterized in that call a specific model-specific subprogram from among said dynamic random access said copied into the memory by referring to the model identification data of the plurality of model-specific sub-program while executing processing in accordance with the main program Solve by equipment.
[0008]
The operation of the present invention will be described below.
In order to reduce the production cost of the CD-ROM, it is conceivable to record a plurality of model-specific execution programs on one CD-ROM. However, since the execution program of the navigation device is relatively large, if a plurality of execution programs are recorded on one CD-ROM, the capacity for recording other data such as map data is reduced.
[0009]
Therefore, in the present invention, the execution file is composed of one main program and a plurality of model-specific subprograms. The navigation device is provided with model identification data generating means, and the model identification data generating means generates model identification data unique to the model. The model identification data generating means is constituted by, for example, a plurality of terminals and resistance elements selectively connected to these terminals, that is, hardware. The processing means identifies the model by the model identification data when operating in accordance with the main program, and calls a specific model-specific subprogram indicated by the model identification data when executing the model-specific processing.
[0010]
In this way, in the present invention, as a navigation device, a part common to each model is processed by the main program, and a part specific to each model is processed by the model-specific subprogram. Can be realized. This reduces the manufacturing cost of a CD-ROM or DVD-ROM (hereinafter simply referred to as “CD-ROM”) and facilitates software management.
[0011]
Note that it takes time to read the model identification data from the model identification data generating means (hardware) every time the process unique to each model is to be executed. For this reason, it is preferable to store the model identification data in a dynamic random access memory (hereinafter referred to as DRAM). However, the data stored in the DRAM disappears when the power is turned off. In addition, data stored in the DRAM may be rewritten during operation due to noise or the like. If the model identification data stored in the DRAM is rewritten, a malfunction may occur such that a sub-program for another model is executed and a display screen for another model is displayed.
[0012]
In order to prevent such a problem, in the present invention , the model identification data acquired from the model identification data generating means is copied to the nonvolatile memory. At this time, it is preferable to read the data from the model identification data generating means a plurality of times and use the value with the highest appearance frequency as the model identification data. Then, the model identification data stored in the non-volatile memory is copied to the DRAM, and the model identification data stored in the DRAM is referred to when calling the subprogram for each model during execution of the execution program.
[0013]
In the invention described in claim 3 , the model identification data stored in the DRAM and the model identification data stored in the nonvolatile memory are periodically compared, and the model recorded in the DRAM. Check whether there is any abnormality in the identification data. As a result, it is possible to reliably avoid executing the model-specific subprograms for other models.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing a navigation device according to an embodiment of the present invention. In the present embodiment, as shown in FIG. 2, a case where three types of navigation devices A, B, and C are operated by a common execution program A will be described. The specifications of the hardware A1, A2, and A3 of the navigation devices A, B, and C are basically the same, and detailed specifications (for example, the presence / absence of ports for connecting to other devices, I / O ports described later) Only the presence or absence of chip resistors connected to the 12 terminals a to d) is slightly different.
[0015]
A CPU 11, an input / output (I / O) port 12, an SRAM (Static Random Access Memory) 13, a flash memory 14, a DRAM 15, an interface 16, and the like are connected to the common bus line 20. Data is sent and received between each other. The common bus line 20 is also connected to an interface (not shown) connected to the GPS receiver, an interface (not shown) connected to the display, and the like.
[0016]
The I / O port 12 generates different model identification data for each model (each navigation device A, B, C). That is, the I / O port 12 has four terminals a to d, and a chip between these terminals a to d and the power supply line Vcc depends on the models A, B, and C of the navigation device. A resistor 18 is selectively connected. For example, as shown in FIG. 3, in the navigation device A, the chip resistor 18 is connected only to the terminal c, in the navigation device B, the chip resistor 18 is connected only to the terminal b, and in the navigation device C, to the terminals b, c, and d. A chip resistor 18 is connected. The I / O port 12 uses 4-bit model identification data with “1” as the terminal to which the power supply voltage is input via the chip resistor 18 and “0” as the terminal to which the chip resistor is not connected. That is, since the connection state of the chip resistor is different for each model, the model can be identified by the model identification data. In the present embodiment, the least significant bit of the model identification data is a parity bit.
[0017]
The flash memory 14 is a rewritable memory, and this flash memory 14 stores an execution program for operating hardware as a navigation device. The SRAM 13 is a non-volatile memory for storing model identification data and an error history, which will be described later. The SRAM 13 is backed up by a battery (not shown) and stored even when the power of the navigation device is turned off. Holds identification data. The DRAM 15 is also a memory for storing model identification data. The DRAM 15 loses data when the power of the navigation device is turned off.
[0018]
The interface 16 is connected to the CD-ROM drive device 17 and outputs the upgrade program or map data read from the CD-ROM loaded in the CD-ROM drive device 17 to the bus line 20. The CPU 11 detects the current position of the vehicle from the GPS signal received by the GPS receiver according to the execution program stored in the flash memory 14, draws a map image based on the map data read from the CD-ROM, A guidance route to the destination is searched using the current position of the vehicle as a departure point, and various guidance information is displayed on the display in order to guide the vehicle to the destination along the guidance route. At the time of version upgrade, the CPU 11 reads the version upgrade program from the CD-ROM and writes it in the flash memory 14.
[0019]
FIG. 4 is a schematic diagram showing a configuration of an execution program of the navigation device of the present embodiment. This execution program includes one main routine (main program), three model-specific subroutines (model-specific subprograms) A, B. C. The CPU 11 executes processing according to the main routine, inputs model identification data from the I / O port 12, and copies it to the SRAM 13 and the DRAM 15. When different processing is required for each model, model type subroutines to be called from the main routine are selected with reference to model identification data stored in the DRAM 15. The model-specific subroutine A is a subroutine for the navigation device A, and describes a program for realizing functions unique to the navigation device A, unique display, transition timing, and the like. Similarly, the model-specific subroutines B and C describe programs for realizing functions unique to the navigation devices B and C, unique display and transition timing, respectively.
[0020]
FIG. 5 is a flowchart showing the operation of the navigation device of this embodiment when the power is turned on, and FIG. 6 is a schematic diagram showing the transition of model identification data.
First, when the power of the navigation device is turned on, the CPU 11 copies the model identification data from the SRAM 13 to the DRAM 15 in step S1. Then, the process proceeds to step S2, and it is checked whether or not copying has been performed normally. If the copying is not performed normally, for example, if the data stored in the DRAM 15 is “0000” (at the time of factory shipment or when the SRAM is cleared), the process proceeds to step S 3, and the model identification data is normal in the DRAM 15. If it has been copied, the process proceeds to step S8.
[0021]
If copying of the model identification data to the DRAM 15 fails in step S2, the CPU 11 reads the data stored in the SRAM 13 in step S3 and checks whether the data is empty (“0000”). If the data is not empty, the process proceeds to step S4 to leave an error history in the SRAM 13, and then the process proceeds to step S5. On the other hand, when the data is empty in step S3, the process directly proceeds from step S3 to step S5. Here, when the error history is unnecessary, steps S3 and S4 may be omitted.
[0022]
In step S <b> 5, the CPU 11 reads model identification data from the I / O port 12 and stores it in the SRAM 13. At this time, in order to prevent the occurrence of an error, the CPU 11 reads the model identification data from the I / O port 12 11 times, and stores the value with the highest appearance frequency in the SRAM 13 as normal model identification data. Then, the model identification data is copied from the SRAM 13 to the DRAM 15.
[0023]
Next, the process proceeds to step S6, and the CPU 11 checks whether or not the data stored in the SRAM 13 and the DRAM 15 has a parity error. If there is a parity error, the process proceeds to step S7 and an error history is left in the SRAM 13, and then the process proceeds to step S8. On the other hand, if no parity error has occurred in step S6, the process directly proceeds from step S6 to step S8. Here, when the error history is unnecessary, steps S6 and S7 may be omitted.
[0024]
In step S8, the CPU 11 performs predetermined processing (for example, detecting the current position of the vehicle from the GPS signal received by the GPS receiver according to the execution program written in the flash memory 14, or obtaining map data around the current position of the vehicle. Read out from the CD-ROM and draw a map). If necessary, the model identification data stored in the DRAM 15 is referred to, and the model-specific subroutine indicated by the model identification data is called to execute the model-specific processing.
[0025]
During this time, the CPU 11 periodically compares the model identification data stored in the DRAM 15 and the SRAM 13 respectively. That is, in step S9, the CPU 11 checks whether or not a predetermined time (for example, 10 minutes) has elapsed. If it has elapsed, the process proceeds to step S10, and the model identification data stored in the DRAM 15 and the SRAM 13 are compared. To do. And when both values correspond, it returns to step S8 and continues processing. On the other hand, if the values do not match, the process proceeds to step S11 and the error history is stored in the SRAM 13. Here, step S11 may be omitted when the error history is unnecessary. Thereafter, the process returns to step S1, the model identification data is copied from the SRAM 13 to the DRAM 15, and the processes in and after step S2 are repeated.
[0026]
In the present embodiment, since the execution program can be made common to all models, it is not necessary to create a CD-ROM for each model when upgrading the version. Thereby, the production cost of CD-ROM is reduced. In addition, the required storage capacity can be reduced as compared with the case where the execution file for each model is stored on one CD-ROM, and a capacity for storing data (such as map data) other than the upgrade program is secured. be able to. Furthermore, since manufacturers can share execution files for a plurality of models, software management becomes easy.
[0027]
In the present embodiment, the model identification data stored in the SRAM 13 and the DRAM 15 are periodically compared. If the two are different, the model identification data is copied from the SRAM 13 to the DRAM 15 again. It is possible to reliably prevent the subroutine for the model from being executed.
Furthermore, in the present embodiment, even if an error occurs in the model identification data, the processing is continued after the error history is stored in the SRAM 13, so that the function as a navigation device is not lost.
[0028]
In the above embodiment, the case where the model identification data stored in the SRAM 13 and the DRAM 15 is compared every 10 minutes has been described. However, the comparison of the model identification data stored in the SRAM 13 and the DRAM 15 is performed as follows. Alternatively, it may be performed every predetermined process, for example, before the process shifts from the main routine to any of the subroutines A, B, and C.
[0029]
In the above-described embodiment, the case where the I / O port 12 and the chip resistor 18 are used as the model identification data generating unit has been described. However, the configuration of the model identification data generating unit is limited to this. Instead, any data that generates model-specific data by hardware may be used.
[0030]
【The invention's effect】
As described above, according to the present invention, model identification data generating means for generating model identification data, and an execution program storage means for storing an execution program composed of a main program and a plurality of model-specific subprograms. And the processing means refers to the model identification data while executing the main program, and calls a specific model-specific subprogram from the plurality of model-specific subprograms. The execution program installed in the apparatus can be shared.
[0031]
In this case, a nonvolatile memory and a dynamic random access memory are provided, and model identification data generated by the model identification data generating means is stored in the nonvolatile memory and the dynamic random access memory, and the model-specific subprogram is stored. The processing speed can be improved by referring to the model identification data stored in the dynamic random access memory when reading. Further, by substituting the model identification data stored in the nonvolatile memory and the dynamic random access memory periodically to check whether there is any abnormality in the model identification data, subprograms for other models Can be reliably prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a navigation device according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing hardware and software configurations of three types of navigation devices according to the embodiment of the present invention.
FIG. 3 is a schematic diagram showing chip resistor connection states and model identification data in the three types of navigation devices.
FIG. 4 is a schematic diagram illustrating a configuration of an execution program of the navigation device according to the embodiment.
FIG. 5 is a flowchart showing an operation of the navigation device of the embodiment when the power is turned on.
FIG. 6 is a schematic diagram showing transition of model identification data in the navigation device of the embodiment.
FIG. 7 is a schematic diagram showing a hardware and software configuration of a conventional navigation apparatus.
[Explanation of symbols]
11 CPU,
12 I / O ports,
13 SRAM,
14 Flash memory,
15 DRAM,
16 interface,
17 CD-ROM drive,
18 Chip resistance,
20 Common bus line.

Claims (4)

In a navigation device that detects the position of a vehicle by a signal from a GPS satellite and displays a map image around the vehicle on a display,
Model identification data generating means for generating model identification data;
Execution program storage means for storing an execution program composed of a main program common to a plurality of models and a plurality of model-specific subprograms;
Processing means for executing processing according to the execution program stored in the execution program storage means ;
A non-volatile memory and a dynamic random access memory ;
The processing means copies the model identification data generated by the model identification data generating means to the nonvolatile memory, and further copies the model identification data copied to the nonvolatile memory to the dynamic random access memory. do it,
Navigation that calls a specific model-specific subprogram from among the plurality of model-specific subprograms with reference to the model identification data copied to the dynamic random access memory during processing according to the main program apparatus.   The navigation apparatus according to claim 1, wherein the model identification data generating means includes a plurality of terminals and resistive elements selectively connected to the terminals. The processing means periodically compares the model identification data stored in the non-volatile memory and the dynamic random access memory, thereby causing an abnormality in the model identification data recorded in the dynamic random access memory. The navigation apparatus according to claim 1 , wherein the presence or absence of a check is checked. 2. The navigation apparatus according to claim 1 , wherein the processing unit reads the model identification data from the model identification data generating unit a plurality of times, and copies a value having the highest appearance frequency to the nonvolatile memory. .

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