JP2012043309A - System module and electric equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a CPU to execute a recovery process for rewriting a boot program while suppressing an increase in an occupation area of a circuit board in a system module constituting a system that includes the CPU executing a prescribed process and a rewritable nonvolatile memory storing the program, to facilitate update work of the boot program in the system, and to facilitate the maintenance of electric equipment where the system is mounted.SOLUTION: The boot program and a recovery program for rewriting the boot program are stored in different memory regions in a same flash memory 202. An operation mode for operating a system module 110 mounted on the electric equipment is set, according to the attitude of the electric equipment, out of a regular mode where the CPU 201 executes the boot program immediately after a power activation and the recovery mode where the CPU rewrites the boot program immediately after the power activation.

Description

  The present invention relates to a system module and an electric apparatus, and more particularly, a system such as a large scale integrated circuit (LSI) including a central processing unit (CPU) that executes a program and a rewritable nonvolatile memory that stores the program. In particular, the present invention relates to a system module that performs a bootload process for recovering the system, and an electric device equipped with such a system module.

  Generally, a liquid crystal display module is rewritable for a boot program and an application that store a microprocessor (control (LSI) CPU for liquid crystal module) that controls the liquid crystal panel and a program executed by the microprocessor. A non-volatile memory.

  An electronic system having such a CPU and a memory storing the program can add functions or improve performance by modularizing or rewriting the boot program or application program in the memory even after commercialization. It is easy to plan.

  By the way, a method well known as a technique for rewriting an application program is a method in which a recovery program for rewriting is placed in the same electrically rewritable nonvolatile memory as the application program. In this method, the application program is rewritten during the execution of the recovery program.

  This method has the advantage of simplifying the system because only one system ROM (flash ROM) is required.

  However, if a power failure or error occurs during rewriting of the boot program stored in the flash ROM and the boot program (starting program part) is destroyed, the system cannot be restarted. .

  As a method for preventing the system from entering such a state in which it cannot be restarted, a method of providing two flash ROMs for storing boot programs is conceivable. In this method, the area occupied on the substrate of the system module is considered. There is a problem that the circuit becomes large and the circuit becomes complicated.

  Therefore, the system reverses a predetermined bit of the address signal transmitted from the CPU to the nonvolatile memory by an external manual switch, and forcibly sets the memory area accessed by the address signal from the CPU as the lowest address area. A method of replacing the central address area with the central address area is conceivable. In a system with such a configuration, if the recovery program is stored in the central address area of the non-volatile memory, the system cannot be restarted even if the boot program stored in the lowest address area is destroyed. Never become.

  In an electronic system having a CPU and a memory storing the program as described above, a memory area accessed by an address signal from the CPU by an external manual switch is disclosed in, for example, Patent Document 1 Such a conventional system will be described below with reference to the drawings.

  FIG. 7 schematically shows such a conventional electronic system.

  The electronic system 200 is used as various modules such as a display module, a printing module, a voice processing module, a communication module, and a control module, which are components of electrical equipment such as electronic information equipment and home appliances. . FIG. 7 shows an electronic system having the program rewriting function as described above.

  More specifically, the electronic system 200 includes a CPU 201 that executes a program to perform various processes as various modules, a boot program for starting an operation system, and the CPU for causing the CPU to perform various processes. An application program and a memory 202 that stores a recovery program for causing the CPU to rewrite the boot program. Here, the CPU 201 and the flash memory 202 can exchange address signals and data signals via the address bus 222 and the data bus 221.

  The electronic system 200 also performs data communication between the manual inversion switch 203 that inverts the higher-order bits of the logical address signal on the address bus 222 from the CPU 201 to the flash memory 202, and the electronic system 200 and an external communication terminal. And a communication device 204 for performing the above. Here, the recovery program causes the CPU 201 to download an updated boot program via the communication device 204 and perform a program rewrite process for overwriting the boot program in the flash memory 202.

  The boot program is stored in the lowest address area from the head address of the storage area of the flash memory 202 to the first intermediate address, and the address from the next address after the first intermediate address to the second intermediate address is stored. An application program is stored in the first intermediate address area, and a recovery program is stored in the second intermediate address area (central address area) from the address next to the second intermediate address to the third intermediate address. Stored. Here, the address is intended to be a logical address, and the address area is intended to be a logical address area.

  Next, the operation will be described.

  In such an electronic system 200, during normal operation, the manual reversing switch 203 is set to pass the address signal from the CPU 201 to the flash memory 202 as it is. In this case, when the power of the electronic system 200 is turned on, the CPU 201 boots from the head address of the lowest address area, and the processing from when the boot program is read into the CPU 201 until the operating system is started is performed. It will be.

  On the other hand, when rewriting the boot program, the manual inversion switch 203 is set to invert the upper few bits of the address signal from the CPU 201 to the flash memory 202.

  In this case, when the electronic system 200 is turned on, the CPU 201 does not boot from the head address of the lowest address area as in normal operation, but boots from the head address of the central address area of the memory 202. become. Thereby, the CPU 201 reads the recovery program, downloads the updated boot program by the communication device 204 according to the program, and overwrites the boot program in the flash memory 202 with the updated boot program.

  In this way, the boot program is stored in the lowest address area of the memory, and the recovery program for rewriting the boot program is stored in the central address area of the memory, and is stored in the lowest address area during normal operation. When the CPU boots from the boot program and the boot program is rewritten, the boot program is accidentally destroyed by causing the CPU to boot from the recovery program stored in the central address area. By setting the manual reversing switch, it is possible to boot from the recovery program that is never rewritten, and the CPU can normally enter the boot program rewriting routine.

JP 2001-195260 A

  However, in the system having the boot program rewriting function disclosed in Patent Document 1, since the address signal from the CPU to the flash memory is inverted by a manual switch, this switch must be operated when the boot program is updated. I must.

  Normally, a manual switch is incorporated in a module as an electronic system and mounted in a product casing, so that it is necessary to distinguish it from other switches during operation, which is necessary for commercialization. This is a problem in facilitating maintenance.

  In other words, when performing the update work required to maintain the electrical equipment in a normal state, it is easy to open the electrical equipment casing and operate the switches attached to the module board inside the casing. It is not work.

  When the user opens the housing of the electrical device and performs a simple cleaning operation, the normal operation and the recovery operation (boot program rewriting operation) attached to the module board inside the housing are switched. There is a possibility that the boot switch may be inadvertently switched by operating the manual switch by mistake, and switching between the normal operation and the recovery operation by the manual switch has a problem in ensuring safety against the erroneous operation.

  The present invention has been made to solve the above-described problems, and can realize a recovery process for rewriting a boot program while suppressing an increase in the occupied area of the board, and further, an update operation of the boot program in the system It is an object of the present invention to obtain a system module capable of facilitating maintenance of an electric device in which this system is mounted, and an electric device in which such a system module is mounted.

  A system module according to the present invention is a system module that has a central processing unit and constitutes a system that performs various types of information processing, and a boot program for starting an operation system and a process for rewriting the boot program And a recovery program that causes the central processing unit to be stored in different memory areas, and a rewritable non-volatile memory in the housing and an operation from outside the housing of the electrical equipment equipped with the system. The operation information transmitted to the system detects whether the operation mode at the time of system startup should be the recovery mode instead of the normal mode, and the detection output of the mode detector determines the recovery mode. When the central processing unit reads the recovery program, Are those having an address signal switching unit for switching the address signal the central processing unit to generate, the objects can be achieved.

  According to the present invention, in the system module, the boot program is stored in a lower memory area from a lowest address of the nonvolatile memory to a first address that is an upper address thereof, and the recovery program is stored in the nonvolatile memory Preferably, it is stored in the highest memory area from the second address higher than the first address to the highest address.

  According to the present invention, in the system module, the address signal switching unit is provided in an address bus between the central processing unit and the nonvolatile memory, and an address control signal which is a detection output of the mode detector is When indicating the recovery mode, the value of the upper bit consisting of a plurality of bits in the address signal is fixed to a predetermined value so that the address signal generated by the central processing unit indicates the uppermost memory area. preferable.

  In the system module, when the address control signal that is the detection output of the mode detector indicates the normal mode, the central processing unit is reset when the reset of the central processing unit is released after the system is turned on. The arithmetic processing unit executes the boot program stored in the lowest memory area in the non-volatile memory, and when the address control signal that is the detection output of the mode detector indicates the recovery mode, the system is turned on. When the reset of the central processing unit is later released, it is preferable that the central processing unit executes a recovery program stored in the uppermost memory area in the nonvolatile memory.

  According to the present invention, in the system module, the address signal switching unit is a tri-state that switches between a state of outputting an output signal corresponding to an input signal and a state of outputting a constant output signal regardless of the input signal by a control signal. Element, and a pull-up resistor connected between the output terminal of the tri-state element and a power source, the address control signal is used as the control signal, and the address control signal indicates a recovery state. It is preferable that the output node of the tristate element is set to a high impedance state so that the logical value of the output signal of the tristate element is forcibly fixed to the logical value “1” by the pull-up resistor. .

  According to the present invention, in the system module, the operation from the outside of the casing of the electric device on which the system is mounted is an operation for changing the attitude of the casing of the electric device, and the mode detector is a power source for the system. Detects whether the reference plane is placed parallel to the horizontal or vertical during the reset period of the central processing unit after being turned on, and changes the operation mode at system startup to the normal mode It is preferable to determine whether or not the recovery mode should be set.

  In the system module according to the present invention, it is preferable that an inclination sensor module is used for the mode detector.

  In the system module according to the present invention, it is preferable that a G sensor module is used for the mode detector.

  In the system module, the operation from the outside of the casing of the electric device equipped with the system is an operation of irradiating an optical signal from the outside of the casing of the electric device toward the system in the casing. The mode detector detects the optical signal during the reset period of the central processing unit after powering on the system, and changes the operation mode at system startup to the recovery mode instead of the normal mode. It is preferable to determine whether or not

  In the system module according to the present invention, it is preferable that a light detection sensor module for detecting the optical signal is used for the mode detector.

  The present invention provides the system module, wherein the mode detector includes a light detection sensor that detects the light signal, and analyzes code information included in the light signal based on a detection output of the light detection sensor. Based on the code information, it is preferable to detect whether or not the operation mode at the time of system startup should be the recovery mode instead of the normal mode.

  The electrical device according to the present invention is an electrical device in which a system module is mounted, and the system module is the system module according to the present invention described above, thereby achieving the above object.

  Next, the operation of the present invention will be described.

  In the present invention, data can be rewritten by storing a boot program for starting the operation system and a recovery program for causing the central processing unit (CPU) to rewrite the boot program in different memory areas. System modules that are equipped with a non-volatile memory in either the normal mode in which the CPU executes the boot program immediately after power-on or the recovery mode in which the CPU rewrites the boot program immediately after power-on Since the operation is set according to the attitude of the electric device, no switch operation is required to switch between the normal mode and the recovery mode, and the recovery state can be more easily shifted.

  Furthermore, in the present invention, the address signal is switched to the flash memory by not fixing the signal level by a logic element such as XOR but by fixing the value of the address signal by a tristate element and a pull-up resistor. The number of bits for switching signals can be selected more freely. For this reason, the storage location of the recovery program can be freely selected, thereby enabling efficient placement of the program in the memory area.

  As described above, according to the present invention, in the system module constituting the system having the CPU that performs the predetermined process and the rewritable nonvolatile memory that stores the program, the recovery process in which the CPU rewrites the boot program is performed. This can be realized while suppressing an increase in the area occupied by the board. In addition, it is possible to simplify the update of the boot program in the system and facilitate the maintenance of the electrical equipment on which the system is mounted.

FIG. 1 is a diagram for explaining an electrical device according to Embodiment 1 of the present invention. As an example of an electronic device, a laptop personal computer (FIG. 1A) and an audio device (FIG. 1B) Is shown. FIG. 2 is a diagram for explaining an electric device according to the first embodiment of the present invention, and is a diagram for explaining a system module mounted on the electric device such as a personal computer or an audio device shown in the first embodiment. . FIG. 3 is a diagram for explaining the memory area of the flash ROM constituting the system module of the first embodiment, showing the logical address configuration of the flash memory, and FIG. 3 (a) explaining the normal operation. FIG. 3B is a diagram for explaining the recovery operation. FIG. 4 is a diagram for explaining the fixed switch that constitutes the system module according to the first embodiment of the present invention, and shows an address fixing circuit that fixes the address corresponding to 1 bit constituting the fixed switch 111. . FIG. 5 is a flowchart for explaining the operation of the system module according to the first embodiment of the present invention, in which an operation for executing a normal process by executing a boot program after the power is turned on, and a recovery program being executed after the power is turned on. The operation of rewriting the boot program is shown. FIG. 6 is a diagram for explaining a system module according to the second embodiment of the present invention. FIG. 7 is a diagram for explaining an electronic system having a boot program rewriting function disclosed in Patent Document 1. In FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram for explaining an electric device according to Embodiment 1 of the present invention. As an example of an electronic device, a laptop personal computer (FIG. 1A) and an audio device (FIG. 1B) are used. Show.

  Various system modules constituting these electric devices are mounted on the personal computer 100 shown in FIG. 1A and the audio device 101 shown in FIG.

  For example, various system modules are mounted on the personal computer 100. For example, the motherboard 100b housed in the main body 100a of the personal computer 100 is one system module. The motherboard 100b is equipped with a CPU that performs various processes according to an operation system, a flash ROM (nonvolatile rewritable memory) that stores a program executed by the CPU, and the like. For example, the flash ROM of the motherboard 100b stores a BIOS (Basic Input / Output System) and a boot program for starting an operation system.

  The personal computer 100 is equipped with a liquid crystal display module 100c1 for controlling the liquid crystal panel 100c as a system module. The module 100c1 includes a liquid crystal control CPU that controls the liquid crystal panel, and a flash ROM that stores a boot program and application programs (including an operation system) that are programs executed by the liquid crystal control CPU. .

  The audio device 101 shown in FIG. 1B includes a device main body 101a and a pair of speakers 101b and 101c connected to the device main body.

  Such an audio device 101 is also equipped with a system module, which is an audio CPU that realizes various functions in the audio device in accordance with the operation system, and a program executed by the audio CPU. And a flash ROM storing a boot program and application programs (including an operation system).

  FIG. 2 is a diagram for explaining a system module mounted on an electric device such as a personal computer or an audio device shown in the first embodiment.

  The system module 110 shown in FIG. 2 is similar to the system module constituting the conventional electronic system. The CPU 201 executes various processes as various modules by executing a program, and various boot programs for starting the operation system. And a flash memory 202 storing a recovery program for causing the CPU to perform a process of rewriting the boot program. Here, the CPU 201 and the flash memory (flash ROM) 202 can exchange address signals and data signals (including control signals) via the address bus 222 and the data bus 221.

  In addition, the system module 110 includes a fixed switch 111 that fixes higher-order bits of a logical address signal in the address bus 222 from the CPU 201 to the flash memory 202, and a pull-up resistor 112 connected to the output node of the fixed switch 111. The communication module 204 performs data communication between the system module 110 and an external communication terminal.

  Here, the address bus 222 indicating the logical address from the CPU 201 to the flash memory 202 has a 24-bit configuration. However, since this differs depending on the system, it is not necessarily 24 bits. The lower 16 bits of the address bus 222 are directly connected to the flash memory 202, and the upper 8 bits are connected to the fixed switch 111. A data bus 221 for data signals and control signals other than the address bus 222 is directly connected to the flash memory 202.

  In addition, the recovery program causes the CPU 201 to perform a program rewrite process of downloading an updated boot program via the communication device 204 and overwriting the boot program in the flash memory 202.

  In addition, the system module 110 includes an acceleration sensor module 113 that detects the posture of an electrical device on which the system module 110 is mounted, for example, whether the system module 110 is placed vertically or horizontally, and the acceleration sensor module 113. And a reset IC 114 that transmits a reset release signal 224 to the CPU 201.

  Here, the acceleration sensor module 113 detects the direction of weight acceleration to determine the posture of the electric device, and the reference plane of the system module, for example, the surface of the motherboard, which is the system module board, is horizontal or An address control signal is output depending on whether it is vertical. The fixed switch 111 is configured to block the upper 8 bits of the address when the value of the SW control signal 220 from the acceleration sensor module 206 is 1, and to pass it through when the value is 0. Instead of the acceleration sensor module 113 that detects the direction of weight acceleration, a G sensor module that can detect acceleration in three directions of the X, Y, and Z axes can be used.

  FIG. 3 is a diagram showing a memory area of the flash ROM constituting the system module of the first embodiment, FIG. 3 (a) is a diagram for explaining a normal operation, and FIG. 3 (b) is a recovery operation. FIG.

  The boot program is stored in the lowest address area 232 from the first address (000000H) Ps of the data storage area Mr of the flash memory 202 to the address (00FFFFH). From the subsequent address (010000H) to the intermediate address (FEFFFFH) An application program is stored in the intermediate address area 231, and a recovery program is stored in the highest address area 230 from the second intermediate address (FF00000H) Pr to the final address (FFFFFFH). Here, the address is a logical address generated by the CPU, and each address area is a logical address area for the physical address area of the flash ROM.

  FIG. 4 shows an address fixing circuit for fixing an address corresponding to 1 bit, which constitutes the fixed switch 115.

  The address fixing circuit 115a includes a tristate buffer (tristate element) 211 having an input node connected to an address signal line 222a corresponding to 1 bit in the address bus 222 of the flash memory 202, and an output node of the tristate buffer 211. The output node of the tristate buffer 211 is connected to the flash memory 202. The pull-up resistor 112a is connected to the power source. Here, when the value of the SW control signal 220 is 1, the tri-state buffer 211 outputs the signal level of the address signal line 222 as it is, and when the value of the SW control signal 220 is 0, the output node is in a high impedance state. When the output node of the tristate buffer 211 is in a high impedance state, all the address signals appearing at the output node of the tristate buffer 211 are automatically fixed to 1 by the pull-up resistor 112.

  Next, the operation will be described.

  In an electric device equipped with a system module having such a configuration, for example, the personal computer 100 shown in FIG. 1A, acceleration is applied when the device is in a horizontal use state as shown in FIG. 1A. The sensor module 113 detects that the posture is in the horizontal position, and outputs the SW control signal 220 indicating the value “0” as the detection output.

  On the other hand, when the boot program is being rewritten in the vertical state, the acceleration sensor module 113 detects that the posture is the vertical state, and the SW control signal indicating the value “1” as the detection output. 220 is output.

  In the fixed switch 111, when the value of the SW control signal 220 from the acceleration sensor module 113 is “1”, the upper 8 bits of the address signal are blocked and the value of each bit is fixed to 1, and the SW control signal 220 is set. When the value of “0” is “0”, the address signal is passed as it is.

  Further, the acceleration sensor module 113 outputs an initial operation completion signal 223 to a reset IC 114 for resetting the CPU 201. The reset IC 114 receives the initial operation completion signal 223 and outputs a signal (reset release signal) 224 for releasing the reset of the CPU 201.

  The CPU 201 starts when the reset state is released by the reset release signal 224. When the boot program is rewritten, the CPU 201 starts executing the program from the recovery program 230, and acquires the program from the communication device 204 according to the recovery program 230. Then, the boot program in the flash memory 202 is rewritten.

  On the other hand, at the normal startup time when the boot program is not rewritten, when the CPU 201 starts up, it reads the boot program 232 and starts executing the program.

  Hereinafter, the operation at the time of rewriting the boot program will be described in detail.

  FIG. 5 is a flowchart for explaining the operation of the system module according to the first embodiment of the present invention, in which an operation for executing a normal process by executing a boot program after the power is turned on, and a recovery program being executed after the power is turned on. The operation of rewriting the boot program is shown.

  First, in the first embodiment, an electric device equipped with a system module is operated in either a normal mode in which the CPU executes a boot program immediately after power-on or a recovery mode in which the CPU rewrites the boot program immediately after power-on. Whether to operate is set according to the attitude of the electrical equipment.

  For example, in the case of an electric device, the operation mode of the electric device can be set to the normal mode by setting the electric device in a normal use, which is different from the way in which the electric device is normally used. If the electric device is to be placed, that is, normally used in a horizontal orientation, the operation mode of the electric device can be set to the recovery mode by placing it vertically.

  Therefore, as described above, the electric device is turned on in a normal way or in a different way from normal (step ST1).

  The CPU 201 immediately after the power-on reset of the system is released after the power is turned on is in a reset state, but the acceleration sensor module 113 is released from the reset state before the CPU 201 in that state (step ST2), and the acceleration sensor module 113 is Then, the arrangement state of the system module is determined according to how to place the casing of the electric device (step ST3).

  If the operation mode of the system module is not the recovery mode, the acceleration sensor module 113 sets the value “0” as the SW control signal 220 so that the fixed switch 111 is in an address non-fixed state where the address signal from the CPU 201 is not fixed. Is output (step ST4).

  Next, the acceleration sensor module 113 outputs an initial operation completion signal to the reset IC 114 (step ST4a), and the reset IC 114 receives this and outputs a reset release signal 224 to release the reset of the CPU 201 (step ST5).

  The CPU 201 reads the boot program 232 from the start address 000000H in the address space of the flash memory 202 and starts executing the boot program 232 (step ST6).

  Then, by executing such a boot program, the system module performs normal processing (step ST7).

  As a result of the determination of the system module arrangement state in the acceleration sensor module 113, if the operation mode of the system module is set to the recovery mode, the fixed switch 111 in the acceleration sensor module 113 fixes the address signal from the CPU 201. A signal of value “1” is output as the SW control signal 220 so that the address is fixed (step ST8).

  Thereby, the upper 8 bits of the address signal from the CPU 201 to the flash memory 202 are separated by the tri-state buffer 211 and fixed to 1 by the pull-up resistor 112 (step ST8).

  Thereafter, in the same procedure as in the normal state, that is, the acceleration sensor module 113 outputs an initial operation completion signal to the reset IC 114 (step ST8a), the reset IC 114 receives this and outputs a reset release signal 224 to reset the CPU 201. It is canceled (step ST9).

  The CPU 201 tries to boot from the start address 000000H of the address space of the flash memory 202. However, since the upper 8 bits of the address signal are fixed to 1, the CPU 201 boots from the address FF0000H of the address space of the flash memory 202. Then, execution of the recovery program 230 is started (step ST10).

  Since the recovery program 230 includes a program for rewriting the boot program 232, the CPU 201 downloads the updated boot program through the communication device 204 by executing this recovery program, The boot program 232 stored in the flash memory 202 is overwritten (step ST11).

  If the overwriting ends normally, the CPU 201 performs normal end display (lamp point) (step ST13). This allows the user to know that the boot program has been rewritten. The user confirms this normal end display, puts the casing of the electrical device on which the system module is mounted in a non-recovered state (step ST14), and turns off the power (step ST15).

  After that, by turning on the power (step ST1), the same processing as when not in the recovery state is performed.

  However, if the power supply is cut off during the overwriting of the boot program 232 due to some cause such as a power failure, the normal end display is not reached. At this time, since the CPU 201 does not display a normal end, the user temporarily turns off the power (step ST15), and then turns on the power again with the housing of the electric device set in the recovery mode (step ST1). ).

  As a result, the boot program 232 is rewritten using the recovery program 230 again. At this time, even if the boot program 232 is destroyed due to the abnormal end of the previous rewrite, the destroyed boot program 233 is not used for start-up, so there is no effect. The user can repeat the execution of the recovery program until the boot program rewriting operation is normally completed.

  As described above, in the first embodiment, by switching the address between fixed and non-fixed using the acceleration sensor module, the switch operation is not required for switching between the recovery time and the normal time. can do.

  Also, if the boot program (boot loader) is destroyed when rewriting the program in the flash memory, the recovery boot program can be recovered by switching the memory area address at the start-up after power-on of the CPU as a recovery process. Can be started as a boot program, and a broken boot loader can be repaired.

  In addition, when the boot program is rewritten, the entire system module is often removed from the casing of the electric device and placed in a different manner. In such a case, no special operation is required in the first embodiment of the present invention. In addition, the recovery state can be set and the normal state can be restored.

  Further, in this embodiment, the address signal switching means to the flash memory is not a signal inverting circuit using a logic element such as XOR, but a simplified configuration using a signal fixing circuit using a tristate element and a pull-up resistor. Therefore, the number of address bits to be switched can be selected more freely. For this reason, the storage location of the recovery program can be freely selected, thereby enabling efficient arrangement of the program.

  Further, in this embodiment, the boot program for starting the operation system and the recovery program for causing the central processing unit to perform processing for rewriting the boot program are stored in different memory areas. It is no longer necessary to have a boot program stored in memory and a recovery program stored in memory, and recovery processing can be performed in a single flash memory, thus enabling compactness by reducing the number of ICs in the module. It is.

  In Embodiment 1 described above, the casing of the electrical device may be placed in a non-recovered state after turning off the power, not before turning off the power.

Moreover, in the said Embodiment 1, the operation mode of an electric equipment is set to a normal mode by making it the way of placing an electric device in normal use, and the method of placing the electric device in normal use (landscape orientation) Although the case where the operation mode of the electrical device is set to the recovery mode by placing it in a different way (vertical orientation) from the placement method) is shown, either the normal mode or the recovery mode is set as the operation mode of the electrical device. The method of setting the operation mode according to the orientation of the electrical device is not simply whether the electrical device is horizontally or vertically placed according to Embodiment 1, but the orientation of the electrical device is portrait, landscape, portrait Alternatively, it may be performed according to the number of times the direction is changed, such as landscape orientation.
(Embodiment 2)
FIG. 6 is a diagram for explaining a system module according to the second embodiment of the present invention. The system module according to the second embodiment is also mounted on the electric device such as the personal computer or the audio device shown in the first embodiment. It is.

  A system module 110a shown in FIG. 6 includes an optical sensor module 113a instead of the acceleration sensor module 113 in the system module 110 of the first embodiment, and the other configurations are the same as those of the system module of the first embodiment.

  In other words, in the first embodiment described above, the operation of the electrical device in which the system module 110 is mounted in either the normal mode in which the CPU executes the boot program immediately after power-on or the recovery mode in which the CPU rewrites the boot program immediately after power-on. Whether to operate in the mode is set according to the attitude of the electrical equipment. On the other hand, in the second embodiment, an electric device equipped with the system module 110a is either in a normal mode in which the CPU executes a boot program immediately after power-on, or in a recovery mode in which the CPU rewrites the boot program immediately after power-on. Whether to operate in the operation mode is set in advance based on the optical signal received by the optical sensor module 113a.

  In the system module 110a of the second embodiment having such a configuration, by irradiating light to the optical sensor module 113a housed in the housing of the electric device with a flashlight or the like for a certain time (for example, 10 seconds), By setting the electric device in the recovery mode and irradiating light to the optical sensor module 113a for a certain time (for example, 5 seconds), it is possible to return to the normal mode in which the CPU executes the boot program immediately after the power is turned on.

  Further, by providing code information to the optical signal irradiated to the optical sensor module 113a, the recovery mode can be set only when the optical sensor module 113a is irradiated with the optical signal including the determined code information. Can be returned to the normal mode.

  In the first and second embodiments, the fixing means includes a tri-state element and a pull-up resistor. However, the present invention is not limited to this, and the switching of the address signal to the flash memory is performed by a logic element such as XOR. May be.

  In addition, the above normal end display measures the time from reading the recovery program to the completion of boot program rewrite, and when the boot program rewrite is completed in a shorter time than the preset time set in the timer, the normal end display is displayed. May be performed.

  As mentioned above, although this invention has been illustrated using preferable embodiment of this invention, this invention should not be limited and limited to this embodiment. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  The present invention relates to a system module that constitutes a system such as a large scale integrated circuit (LSI) including a central processing unit (CPU) that executes a program and a rewritable nonvolatile memory that stores the program. In the field of system modules that perform bootload processing to recover the system, and in the field of electrical equipment equipped with such system modules, recovery processing that rewrites the boot program can be realized while suppressing an increase in the occupied area of the board, The update of the boot program in the system module can be simplified, and the maintenance of the electrical equipment in which the system module is mounted can be facilitated.

100 Personal computer (electric equipment)
100a computer main body 100b motherboard 100c liquid crystal panel 100c1 liquid crystal display module 101 audio equipment (electric equipment)
101a Audio device main body 101b, 101c Speaker 111 Fixed switch (tri-state buffer)
112 Pull-up resistor 113 Acceleration sensor module 114 Reset IC
201 CPU
202 Flash memory 204 Communication device 220 Switch control signal 221 Data bus 222 Address bus 223 Initial operation completion signal 224 Reset release signal 230 Recovery program 231 Application program 232 Boot program 233 Corrupted boot program

Claims (12)

A system module having a central processing unit and constituting a system for performing various information processing,
A non-volatile rewritable data memory in which a boot program for starting an operation system and a recovery program for causing the central processing unit to perform processing for rewriting the boot program are stored in different memory areas,
Whether or not the operation mode at the time of starting the system should be set to the recovery mode instead of the normal mode based on the operation information transmitted to the system in the casing by an operation from the outside of the casing of the electric device equipped with the system. A mode detector to detect,
An address signal switching unit that switches an address signal generated by the central processing unit so that the central processing unit reads the recovery program when the detection output of the mode detector indicates the recovery mode. . The system module according to claim 1,
The boot program is stored in a lower memory area from the lowest address of the nonvolatile memory to the first address which is the higher address,
The recovery program is a system module stored in a highest memory area from a second address higher than a first address of the nonvolatile memory to a highest address. The system module according to claim 2, wherein
The address signal switching unit
The address signal generated by the central processing unit when the address control signal, which is provided in the address bus between the central processing unit and the nonvolatile memory and indicates the recovery mode, is the detection output of the mode detector. Is a system module for fixing the value of the upper bit consisting of a plurality of bits in the address signal to a predetermined value so as to indicate the uppermost memory area. The system module according to claim 2, wherein
When the address control signal that is the detection output of the mode detector indicates the normal mode,
When the reset of the central processing unit is released after turning on the system, the central processing unit executes a boot program stored in the lowest memory area in the nonvolatile memory,
When the address control signal that is the detection output of the mode detector indicates the recovery mode,
When the reset of the central processing unit is released after the system is turned on, the central processing unit executes a recovery program stored in the uppermost memory area in the nonvolatile memory. The system module according to claim 3, wherein
The address signal switching unit
A tristate element that switches between a state of outputting an output signal according to an input signal and a state of outputting a constant output signal regardless of the input signal by a control signal, and between the output terminal of the tristate element and a power source A connected pull-up resistor,
When the address control signal is used as the control signal and the address control signal indicates a recovery state, the output node of the tri-state element is forced and the logical value of the output signal of the tri-state element is forced by the pull-up resistor. System module that is in a high-impedance state so as to be fixed at a logical value “1”. The system module according to claim 1,
The operation from the outside of the casing of the electric device equipped with the system is an operation to change the posture of the casing of the electric device,
The mode detector is
After the system is turned on, during the reset period of the central processing unit, it is detected whether the reference plane of the system is placed parallel to horizontal or vertical, and the operation mode at the time of system startup is normally set A system module that determines whether or not a recovery mode should be used instead of a mode. The system module according to claim 6, wherein
A system module in which a tilt sensor module is used for the mode detector. The system module according to claim 6, wherein
A system module in which a G sensor module is used for the mode detector. The system module according to claim 1,
The operation from the outside of the casing of the electric device equipped with the system is an operation of irradiating an optical signal from the outside of the casing of the electric device toward the system in the casing,
The mode detector is
The optical signal is detected during the reset period of the central processing unit after the system is turned on to determine whether the operation mode at the time of system startup should be the recovery mode instead of the normal mode. , System module. The system module according to claim 9, wherein
A system module in which a light detection sensor module for detecting the optical signal is used for the mode detector. The system module according to claim 9, wherein
The mode detector has a light detection sensor for detecting the light signal, analyzes code information included in the light signal based on a detection output of the light detection sensor, and based on the code information, A system module that detects whether or not the operating mode at startup should be the recovery mode instead of the normal mode. An electrical device equipped with a system module,
The electrical apparatus which is a system module in any one of Claim 1 thru | or 11.

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