JP5856220B2 - Navigation system - Google Patents

Description

  The present invention relates to a semiconductor data processing apparatus in which a domain for each central processing unit (CPU) can be set for a resource, and further to a data processing system using the semiconductor data processing apparatus. The present invention relates to a technology effective when applied to an on-chip (SOC) microcomputer.

  Regarding an SOC equipped with a dual-core CPU or the like, when each CPU is used as an asymmetric multiprocessor system (AMP) in which an operating system (OS) is executed, resource conflicts or malfunctions between the CPUs may occur. There is a problem that reliability decreases due to mutual influences and the like. As a technique for solving this problem, there is a technique for improving reliability by realizing so-called “domain separation” in which a domain for each CPU is set for a resource and each access area is protected by hardware. .

  For example, in Patent Document 1, an illegal address access blocking mechanism is inserted between a bus master device and a bus, and a register for setting an address range for permitting access is provided in the illegal address access blocking mechanism, which is output to an address line. A domain separation technique is described in which a comparator determines whether an address within the range is within the range, and if the address is out of the range, illegal address access is blocked by suppressing the output of the control line. The

  Patent Document 2 discloses a central processing unit in which a plurality of virtual machines and virtual machine managers that execute user programs under the control of different operating systems are selectively configured according to information set in a mode register, and the virtual machine A resource access management module that manages access to hardware resources that can be used, and the resource access management module controls information obtained from the set mode register and access to the hardware resources by the central processing unit. A domain separation technique is described in which information is input and whether the access to the hardware resource according to the access control information is controlled by comparing the input information with information set in the control register.

JP 2004-334410 A JP 2008-97173 A

  The domain separation in the above prior art document issues identification information such as an identification ID when each CPU issues access to a resource, and the module that manages the resource detects the identification information and is not set on the resource side. When an attempt is made to access the CPU, access denial or address conversion is performed to protect access to resources and prevent malfunction. In this way, in order to improve the reliability in AMP, it is important to clearly separate the domains of resources and cope with hardware so that resource accesses by mutual CPUs do not interfere.

  However, when this system is reviewed from the product concept side, there are cases where resources cannot always be separated. For example, in a part that depends on HMI (human interface) such as a display or a keyboard interface, even if the system is domain-separated, if sharing of resources is not permitted in part, conspicuousness and operability may occur. It has been found by the inventors. For example, AMP is adopted in the car navigation system, and there are separate CPUs for the control system of vehicle operation information that emphasizes reliability and the information system that handles entertainment and information communication, and the domain is separated into the control system and the information system. If the display device normally displays a map or communication information and is under the control of the information system domain, and wants to transmit critical information from the control system domain, the control system CPU It is necessary to display information using the information system domain by passing necessary information to the information system CPU. When the information CPU is hung up for some reason, it is no longer possible to display critical information, which causes a problem of reduced reliability such as vehicle operation control. On the other hand, if the control system CPU recognizes that the setting state of domain separation is changed whenever necessary, the original purpose of improving the reliability by domain separation may be lost.

  An object of the present invention is to provide a semiconductor data processing apparatus that allows a plurality of CPUs to share some resources while maintaining overall reliability by domain separation.

  Another object of the present invention is to provide a first processing system and a second processing in a data processing system in which a first processing system that requires high reliability and a second processing system that has reduced reliability are mixed. An object of the present invention is to maintain the reliability by domain separation while preventing the first process from being restricted by the second process even if the system shares some resources.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  The following is a brief description of an outline of typical inventions disclosed in the present application.

  That is, an access management circuit that manages access of resource units that are made available to a plurality of central processing units via an internal bus, the access management circuit according to the setting state of a domain setting register, by the central processing unit In a semiconductor data processing apparatus capable of performing domain separation of resource units for each central processing unit by controlling permission and prohibition of access to the resource unit, the access management circuit allows the plurality of central processing units to Some resource units that are selectively allowed to be accessed as shared resources are provided with a control function that allows access by the central processing unit specified by the register setting in preference to access by other central processing units .

  This makes it possible to select a central processing unit that becomes an access subject to a specific resource unit by register setting different from basic domain separation. The selection range is limited to the range of the central processing unit that is permitted to be accessed as a shared resource by domain separation by the access management circuit. Therefore, a part of resources can be shared by a plurality of CPUs while maintaining reliability by domain separation of the entire semiconductor processing apparatus.

  The semiconductor data processing apparatus is applied to a data processing system in which a first processing system that requires high reliability and a second processing system in which reliability is relaxed are mixed. At this time, different central processing units are assigned to the first processing system and the second processing system, and domain separation is performed so that a specific resource unit such as a display controller is shared by both central processing units. If the register setting of the specific resource unit is changed to give priority to access by the central processing unit of the first processing system only when necessary, the first processing system and the second processing system can share some resources. However, it is possible to suppress the first process from being limited by the second process, and it is possible to maintain the overall reliability by the domain separation.

  The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

  That is, according to the semiconductor data processing apparatus of the present invention, it is possible to share some resources among a plurality of CPUs while maintaining the overall reliability by domain separation.

  According to the data processing system of the present invention, in a data processing system in which a first processing system that requires high reliability and a second processing system in which reliability is relaxed are mixed, the first processing system and the first processing system Even if some resources are shared by the two processing systems, it is possible to maintain the reliability by domain separation while suppressing the first processing from being restricted by the second processing.

FIG. 1 is a block diagram illustrating a car navigation system as an example of a data processing system according to the present invention. FIG. 2 is an explanatory diagram showing a setting example of resource allocation for each domain. FIG. 3 is an explanatory diagram illustrating an address map of the microcomputer. FIG. 4 is an explanatory diagram showing a setting example in which “permitted” and “blocked” can be set for each read access and write access as domain assignment. FIG. 5 is an explanatory diagram showing another setting example in which “permitted” and “blocked” can be set for each read access and write access as domain assignment. FIG. 6 is a flowchart illustrating the initial setting operation for the domain setting register. FIG. 7 is a block diagram showing details of the display controller as a specific example of a resource unit that can be made a shared resource of the central processing unit. FIG. 8 is a block diagram showing a specific example of the register interface. FIG. 9 is a flowchart illustrating an operation when the control system and the information system are controlled using the setting change of the priority control register by the microcomputer. FIG. 10 is a block diagram showing another example of a resource unit that can be made a shared resource of the central processing unit. FIG. 11 is a block diagram showing a specific example of the register interface for CPU # 1. FIG. 12 is a block diagram showing a specific example of the register interface for CPU # 0. FIG. 13 is a flowchart illustrating an operation when the control system and the information system are controlled using setting change of the priority control register by the microcomputer adopting the configuration of FIG.

1. First, an outline of a typical embodiment of the invention disclosed in the present application will be described. Reference numerals in the drawings referred to in parentheses in the outline description of the representative embodiments merely exemplify what are included in the concept of the components to which the reference numerals are attached.

  [1] The semiconductor data processing apparatus (1) includes a plurality of central processing units (10, 11), an internal bus (60) to which the central processing unit is connected, and the plurality of central processing units via the internal bus. A resource unit (40 to 51) that is made available to the central processing unit; and an access management circuit (20 to 31) that manages access of the resource unit by the central processing unit. The access management circuit controls permission and prohibition of access to the resource unit by the central processing unit according to the setting state of the domain setting register (65). Among the resource units, some resource units (40, 41) that are selectively allowed to be accessed as shared resources of the plurality of central processing units by the access management circuit are prioritized by a predetermined central processing unit. The priority control register (100C) in which the control data can be written and the access by the central processing unit specified by the priority control data written in the priority control register have priority over the access by other central processing units. And a control circuit ((80 to 82, 85, 86), (120 to 122, 112)) for performing the permitted control.

  This makes it possible to select a central processing unit that becomes an access subject to a specific resource unit by register setting different from basic domain separation. The selection range is limited to the range of the central processing unit that is permitted to access as a shared resource by domain separation by the domain setting register of the access management circuit. Therefore, a part of resources can be shared by a plurality of CPUs while maintaining reliability by domain separation of the entire semiconductor processing apparatus.

  [2] In the semiconductor data processing apparatus according to item 1, the predetermined central processing unit initializes the priority control register.

  Limiting operations to a single central processing unit that controls high priority processing is convenient for maintaining the reliability of domain separation.

  [3] In the semiconductor data processing device according to item 2, each of the plurality of central processing devices uses the resource unit under management of a unique operating system.

  It becomes easy to mount a plurality of central processing units to exhibit the significance of improving data processing efficiency.

  [4] In the semiconductor data processing apparatus according to item 3, the predetermined central processing unit is activated by power-on (S1) and performs initial setting of the domain setting register (S2), and then the predetermined central processing unit The CPU starts its own operating system (S3) and starts another central processing unit (S4). After the startup, the other central processing unit starts its operating system (S5).

  By realizing such an orderly startup sequence in the semiconductor data processing apparatus itself, the occurrence of a situation in which the domain separation process changes undesirably due to the influence of other central processing measures or the operating system in advance. Help to prevent.

  [5] In the semiconductor data processing device according to item 1, the partial resource unit (40) includes a register set (100) used for processing of the resource unit. The control circuit includes a plurality of address decoders (80, 81) for mapping the register set to different address areas for each central processing unit recognized as a shared resource by the access management circuit, and the respective address decoders Decoder output selection circuit (82) for validating the output signal of the address decoder corresponding to the central processing unit specified by the priority control data among the decoded signals, and the output signal selected by the decoder output selection circuit And a register access control circuit (85, 86) for controlling access to the registers of the register set.

  As a result, the physical circuit of the register set can be made common to a plurality of central processing units that are recognized as shared resources, which can contribute to a reduction in circuit scale. However, in the domain separation by the access management circuit, access to the register set by the central processing unit that is not blocked by the control circuit but not permitted by the control circuit will cause an error.

  [6] In the semiconductor data processing device according to item 6, the predetermined central processing unit saves information held in the register set to the memory when the priority control data of the priority control register is changed, and stores the register set information in the memory. When the priority control data in the priority control register is restored to the original when the data is saved, the information saved in the memory is returned to the register set.

  Although the above access error occurs, the original display control can be easily started by saving and restoring the register information.

  [7] In the semiconductor data processing device according to item 1, the partial resource units are prepared in a number equal to the number of central processing devices that are recognized as shared resources by the access management circuit. It has a plurality of register sets (100A, 100B) used. The control circuit includes a plurality of address decoders (120) for mapping the register set corresponding to each central processing unit recognized as a shared resource by the access management circuit to different address areas, and decoding of the address decoder Register access control circuits (121, 122) for controlling access to the registers of the corresponding register set based on the signal, and registers for connecting the register set specified by the priority control data from the plurality of register sets to the processing circuit And a selection circuit (112).

  Although it cannot contribute to the reduction of the circuit scale due to the common register set as in Item 5, the access is not blocked by the domain separation by the access management circuit, but is not permitted by the control circuit. Access to the register set does not cause an error.

  [8] In the semiconductor data processing device according to item 7, the predetermined central processing unit saves information held in the register set to a memory when the priority control data in the priority control register is changed, and stores the register set information in the memory. When the priority control data in the priority control register is restored to the original when the data is saved, the information saved in the memory is returned to the register set.

  By saving and restoring the register information, the original display control can be easily started.

  [9] In the semiconductor data processing device according to item 1, as a part of the plurality of resource units, a direct memory access controller (47, 47) that controls data transfer according to an initial setting by the plurality of central processing devices. 48).

  In domain separation by the domain setting register, the central processing unit to be initialized and the direct memory access controller to be initialized must belong to the same domain.

  [10] The semiconductor data processing device according to [1] includes a display controller (40) and an audio controller (41) as a part of resource units recognized as shared resources of the plurality of central processing units. Other resource units include an image recognition processing circuit (51) and a plurality of external communication interface controllers (42).

  [11] The data processing system includes a semiconductor data processing device (1) and a display (2) controlled by the semiconductor data processing device. The semiconductor data processing apparatus includes a plurality of central processing units, an internal bus to which the central processing unit is connected, and a resource unit that is made available to the plurality of central processing units via the internal bus, An access management circuit for managing access of the resource unit by the central processing unit. The access management circuit controls permission and prohibition of access to the resource unit by the central processing unit according to a setting state of a domain setting register. Among the resource units, a display controller (40) is provided as a part of resource units that are recognized as shared resources of the plurality of central processing units by the access management circuit. A priority control register in which priority control data can be written by the processing device, and an access by the central processing unit specified by the priority control data written in the priority control register has priority over an access by other central processing devices. And a control circuit for performing control to permit.

  For example, assume a data processing system in which a first processing system such as a device control system that requires high reliability and a second processing system such as an information display system in which reliability is more relaxed are mixed. Different central processing units are assigned to the first processing system and the second processing system, and domain separation is performed so that the display controller is a shared resource of both the central processing units. If the priority control register setting of the display controller is changed so that the access by the central processing unit of the processing system is prioritized, an emergency situation occurs in the first processing even if the display controller is shared by the first processing system and the second processing system Can be suppressed from being limited by the second processing such as video image display, and overall reliability by domain separation can be maintained.

  [12] The data processing system according to [11] further includes a video camera (5) for supplying a video signal to the semiconductor data processing apparatus. The semiconductor data processing apparatus includes a video signal input circuit (50) for inputting the video signal, and an image recognition processing circuit (51) for performing image processing for image recognition based on the video signal input from the video signal input circuit. It has further. The predetermined central processing unit performs image recognition based on processing data from the image recognition processing circuit, and instructs the display controller to display a warning on the display device according to an image recognition result.

  [13] The data processing system according to item 12 further includes a vehicle control unit (4) that receives an output of the semiconductor data processing device. The semiconductor data processing apparatus further includes an external communication interface controller (42) for outputting control data to the vehicle control unit. The predetermined central processing unit causes the display controller to output warning display data from the display controller to the display device, and causes the external communication interface controller to output control data for coping with the warning to the vehicle control unit.

  [14] A data processing system according to another aspect includes a semiconductor data processing device and an audio amplifier (3) for inputting an audio signal output from the semiconductor data processing device. The semiconductor data processing apparatus includes a plurality of central processing units, an internal bus to which the central processing unit is connected, and a resource unit that is made available to the plurality of central processing units via the internal bus, An access management circuit for managing access of the resource unit by the central processing unit. The access management circuit controls permission and prohibition of access to the resource unit by the central processing unit according to a setting state of a domain setting register. An audio controller (41) that outputs the audio signal as a part of the resource unit that is recognized as a shared resource of the plurality of central processing units by the access management circuit; The controller includes a priority control register in which priority control data can be written by a predetermined central processing unit, and access by the central processing unit specified by the priority control data written in the priority control register. And a control circuit for performing control to permit the access with priority over the access by.

  For example, assume a data processing system in which a first processing system such as a device control system requiring high reliability and a second processing system such as an audio system whose reliability is more relaxed than that are mixed. Assign a different central processing unit to the processing system and the second processing system, and perform domain separation so that the audio controller is a shared resource of both central processing units. The first processing is performed only when necessary, such as in an emergency. If the setting of the priority control register of the audio controller is changed so as to give priority to access by the central processing unit of the system, even if the audio controller is shared between the first processing system and the second processing system, an emergency situation occurs in the first processing Warnings can be prevented from being limited by secondary processing such as audio output, and overall reliability through domain separation can be maintained. The

  [15] The data processing system according to item 14 further includes a video camera (5) for supplying a video signal to the semiconductor data processing apparatus. The predetermined central processing unit performs image recognition based on data processed by the image recognition processing circuit, and instructs the audio controller to issue a warning to the audio amplifier according to an image recognition result.

  [16] The data processing system according to item 15 further includes a vehicle control unit (4) that receives an output of the semiconductor data processing device. The semiconductor data processing apparatus further includes an external communication interface controller (42) for outputting control data to the vehicle control unit. The predetermined central processing unit causes the display controller to output warning utterance data from the display controller to the audio amplifier, and causes the external communication interface controller to output control data for dealing with the warning to the vehicle control unit.

2. Details of Embodiment FIG. 1 illustrates a car navigation system as an example of a data processing system according to the present invention. The car navigation system shown in the figure includes a microcomputer (MCU) 1 as an example of a data processing apparatus according to the present invention, a video camera 5, a TV tuner (TV tuner) 7, a DDR SDRAM (Double-Data-Rate Synchronous Dynamic). A memory 8 such as a random access memory, a liquid crystal display 2, an audio amplifier 3, and a vehicle control unit 4 are connected. Although not particularly limited, the microcomputer 1 performs image recognition using image data photographed by the video camera 5, and displays a guidance for assisting vehicle operation on the liquid crystal display 2 based on the recognition result or an audio amplifier. The vehicle control unit (ECU) 4 that performs electronic control such as automobile engine control and brake assist is controlled based on the image recognition result.

  The microcomputer 1 includes two central processing units (CPU # 0, CPU # 1) 10 and 11 that execute application programs by different OSs (operating systems), and the resources of the central processing units 10 and 11 are used. As a certain resource unit, for example, a display controller 40, an audio controller 41, serial communication interface controllers (SCI # 0, SCI # 1) 42, 43, timers (TMR # 0, TMR # 1) 44, 45, a memory controller SDRAM controller 46, direct memory access controllers (DMAC # 0, DMAC # 1) 47, 48, video input circuits (VIN # 0, VIN # 1) 49, 50, and an image recognition processing circuit 51. . These resource units 40 to 51 are accessed and used by the central processing units 10 and 11 via the internal bus 60. The central processing units (CPU # 0, CPU # 1) 10 and 11 may have only basic functions such as instruction fetch, instruction decode and calculation. In addition to these basic functions, A circuit configuration such as a so-called CPU core including a non-volatile memory storing a basic program such as SRAM or OS as a memory and an accelerator such as a floating-point arithmetic unit may be used. The system controller (SYSCNT) 12 performs a microcomputer startup sequence and operation mode control at the time of power-on. Although not particularly limited, the central processing unit (first central processing unit, CPU # 0) 10 is used for control of a control system for vehicle operation control that requires high reliability, and the central processing unit (second central processing unit). The apparatus, CPU # 1) 11 is used for control of an information system for audio / video control in which required reliability is relaxed compared to the control system.

  The microcomputer 1 includes access management circuits (ACCSC # 0 to ACCSC # 11) 20 to 31 that perform access management for domain separation on resources used by the plurality of central processing units 10 and 11. Here, the access management circuits (ACCSC # 0 to ACCSC # 11) 20 to 31 are illustrated in a one-to-one correspondence with the resource units 40 to 51. In this example, the domains are a control system domain (a resource unit group used for control of the control system) that is controlled by the central processing unit (CPU # 0) 10 and an information system that is controlled by the central processing unit (CPU # 1) 11. It is divided into domains (resource units used for information system control). For example, FIG. 2 shows a setting example of resource allocation for each domain. A circle indicates that the resource is assigned to the corresponding domain. In this domain assignment, the display controller 40, the audio controller 41, and the SDRAM controller 46 are shared resources that can be used by any of the central processing units 10 and 11.

  FIG. 3 illustrates an address map of the microcomputer. Domain assignment as described in FIG. 2 is performed for the domain setting register 65 as illustrated in FIG. In the example of FIG. 3, “permission” or “blocking” is meant for each of the “CPU # 0”, “CPU # 1”, “DMAC # 0”, and “DMAC # 1” columns in the “access control” column. Domain assignment is performed by setting a code to perform. “Allowed” means that the central processing unit of the corresponding domain is an available resource, and “Block” means that the central processing unit of the corresponding domain is an unusable resource. In DMAC # 0 and DMAC # 1, the resource unit used by the central processing unit is set as a transfer target in the domain of the central processing unit that is initially set and used, and resources that cannot be used by the central processing unit are transferred. It cannot be. Only the central processing unit (CPU # 0) 10 performs setting for the access access management circuits 20-31. The access management circuits 20 to 31 are not particularly limited. However, the access management circuits 20 to 31 invalidate the access to the access to the resource unit for which blocking is set, and return an error response to the central processing unit that is the access request source.

  In FIG. 3, addresses assigned to resources are illustrated, but this may be fixed or variable by register setting. In FIG. 3, the address of the resource is the memory address of the memory (DDRSDRAM) 8 for the memory controller 46 and the address of the register set for the other circuits. The register set is a register used for the operation of the processing circuit of each resource unit and means a plurality of registers arranged in the address space of the central processing unit. Here, resource addresses that can be set as shared resources differ depending on the domain. For example, the DDR SDRAM 8 is separated into 00000h-3FFFFh and 40000h-7FFFFh. The display controller 4 is separated into a display controller register set 100A of F0000h-F07FFh and a display controller register set 100B included in F0800h-F0FFFh. The audio controller 41 is divided into an audio controller register set 101A of F1000h-F17FFh and an audio register set 101B included in F1800h-F1FFFh. Although details will be described later, a register set mapped to a different address for each domain of the shared resource is not particularly limited, but may be configured to include a physically different register set for each address mapping (described later). The configuration shown in FIG. 10 may be a configuration in which different addresses are physically mapped to one register set (the configuration shown in FIG. 8 described later). Register sets 102 to 110 are arranged in the other resource units 42 to 45 and 47 to 51, and addresses illustrated in FIG. 3 are mapped thereto.

  4 and 5 show another example of domain assignment. Domain assignment is not limited to “permitted” and “blocked” as shown in FIG. 3, but “permitted” and “blocked” are performed for each read access and write access as in the examples of FIGS. It may be settable. The access management circuit 20 returns an error response separately from the read data, or always returns a fixed value, for example, all bits 0, when an illegal read access to a resource unit that is set to block read access occurs, or A fixed value such as all 0s is returned along with the error response. The access management circuit 20 invalidates the write data and returns an error response or only invalidates the write data when an unauthorized write access to the resource unit for which the write access block is set occurs. . The “permitted” and “blocked” settings for each read access and write access are naturally applicable to domain settings for other resource units.

  FIG. 6 illustrates a flowchart of an initial setting operation for the domain setting register 65. When operating power is turned on to the microcomputer 1, the inside is reset by hardware, one central processing unit 10 is activated, and the other central processing unit 11 is set in a standby state (S1). The activated central processing unit 10 executes a program from a predetermined program start address, and initializes the domain setting register 65 of the access control circuits 20 to 31 (S2). Thereafter, the central processing unit 10 itself The operating system is started (S3). In parallel with this, the central processing unit 10 releases the standby state of the other central processing unit 11 and starts up (S4), and after starting up, the central processing unit 11 starts up its own operating system (S5).

  By realizing such an ordered startup sequence in the microcomputer 1 itself, the domain separation processing by one central processing unit (CPU # 0) 10 is affected by other central processing measures and the operating system. This helps to prevent the occurrence of undesired changes.

  FIG. 7 shows details of the display controller 40 as a specific example of resource units that can be shared resources of the central processing units 10 and 11. In FIG. 7, the display controller 40 is divided into a register interface 70 and a display control circuit 71 for convenience, so that it is easy to understand a configuration for avoiding access conflict by priority control for a register set in a shared resource. In the register interface 70, a configuration for an interface between the register in the display controller 70 and the outside is collectively shown. The display control circuit 71 is a generic term for circuits other than the register interface 70.

  FIG. 8 shows a specific example of the register interface 70. As described above, the display controller 40, which is a resource unit that can be made a shared resource of both the central processing units 10 and 11 by the access management circuits 20 to 31, has priority control data by the predetermined central processing unit 10. Is provided with a priority control register 100C which is made writable. The priority control register 100C performs control to permit access by one of the central processing unit 10 or the central processing unit 11 specified by the priority control data written therein with priority over access by the other central processing unit. Used to do. In order to perform this control, an address decoder 80, 81, a decoder output selection circuit 82, a register write control circuit 85 as an access control circuit for the register set 100, and a register read control circuit 86 are provided. The address decoder 81 has decoding logic for mapping the register set 100 and the priority control register 100C to the addresses F0800h to F0FFFh in FIG. 3, and the address decoder 8 has decoding logic for mapping the register set 100 to the addresses F0000h to F07FFh in FIG. . The address decoders 80 and 81 decode the input address signal according to the decoding logic to generate a register selection signal included in the register set 100 and a register selection signal of the priority control register 100C. When the priority control data S1 set in the priority control register 100C indicates CPU # 0, the decoder output selection circuit 82 selects the register selection signal of the register set 100B output from the address decoder 81, and the priority control register 100C. When the priority control data S1 set to 1 indicates CPU # 1, the register selection signal of the register set 100A output from the address decoder 80 is selected. The register write control circuit 85 and the register read control circuit 86 receive the register selection signal output from the decoder output selection circuit 82, and when the write operation is instructed by the read / write signal RW, the register write control circuit 85 Register write data is written to the register set 100 according to the register selection signal, and when a read operation is instructed by the read / write signal RW, the register read control circuit 86 reads the register read data from the register set 100 according to the register selection signal. A register write control circuit 83 and a register read control circuit 84 are used for access control of the priority control register 100C. The register write control circuit 83 and the register read control circuit 84 receive the selection signal of the priority control register 100C from the address decoder 81, and when the write operation is instructed by the read / write signal RW, the register write control circuit 83 registers The priority control data is written to the priority control register 100C according to the selection signal, and when the read operation is instructed by the read / write signal RW, the register read control circuit 84 reads the priority control data from the priority control register 100C according to the register selection signal. . The logical sum circuit 87 forms a logical sum signal of the output of the register read control circuit 84 and the output of the register read control circuit 87.

  Although not specifically shown, the audio controller 41 can be configured in the same manner.

  As a result, the access to the specific resource units 40 and 41 becomes the subject of access by register setting for the priority control register 100C different from the basic domain separation control by the access management circuits 20 and 21 according to the setting of the domain setting register 65. A central processing unit can be selected. The selection range is limited to the range of the central processing units 10 and 11 that are permitted to be accessed as shared resources by domain separation by the domain setting register 65. Changing the setting of the priority control register 100C has no effect on the other domain separation states. In addition, the setting of the priority control register 100C can be changed by using only one central processing unit 10. Therefore, a part of the resources 40 and 41 can be shared by the plurality of central processing units 10 and 11 while maintaining the reliability by domain separation of the entire microcomputer 1. In addition, the physical circuit of the register set 100 can be shared by a plurality of central processing units 10 and 11 that are recognized as shared resources, which can contribute to a reduction in circuit scale. However, in the domain separation by the access management circuit, access to the register set 100 by the central processing unit that is not blocked by the priority control register 100C but is not permitted to access causes an error. If there is no access to the register set 100 during that time, there is no problem.

  FIG. 9 illustrates an operation flow when the control system and the information system are controlled using the setting change of the priority control register by the microcomputer 1. Here, a central processing unit (CPU # 0) 10, a central processing unit (CPU # 1) 11, a display controller 40, an audio controller 41, a serial communication interface controller (SCI # 0) 42, and a video input circuit (VIN) # 1) The operation of 49 is exemplified. It is assumed that the domain setting register 65 is initialized as shown in FIG. At time t0, priority control data for prioritizing the central processing unit (CPU # 1) 11 is set in the priority control register 100C. The central processing unit (CPU # 1) 11 performs register settings for the register sets 100A and 101A, controls navigation image display and TV display on the liquid crystal display 2 according to the register settings, and controls music reproduction by the audio amplifier 3 and the like. Yes.

  The image recognition processing circuit 51 always executes image processing for image recognition in the background of the central processing unit (CPU # 0) 10. Image data processed by the image recognition processing circuit 51 is input by the central processing unit 10 to perform image recognition processing. As a result, if a danger is detected at time t1, the central processing unit (CPU # 0) 10 communicates with the vehicle control unit 4 using the serial communication interface controller (SCI # 0) 42, and brake assist is performed. And settings such as engine control. At the same time, the central processing unit 10 changes the priority control register 100C of the display controller 40 and the audio controller 41 to a setting for giving priority to the CPU # 0 (time t2), and information on the register set (100) of the display controller 40 and the audio controller 41. Are saved in the SDRAM 8, and then new control data and the like are set in the register set (100) of the display controller 40 and the audio controller 41 (time t3). As a result, the central processing unit (CPU # 0) 10 generates warning message and warning voice data and supplies them to the display controller 40 and the audio controller 41. Is displayed on the liquid crystal display 2 and a warning sound is generated by using the audio amplifier 3 based on the control data set in FIG. During this time, the central processing unit (CPU # 1) 11 is ignored even if it accesses the register set of the display controller 40 and the audio controller 41, but the navigation process can be continued. When the central processing unit 10 detects the danger avoidance based on the processed image data by the image recognition processing circuit 51, the central processing unit (CPU # 0) 10 now passes through the serial communication interface controller (SCI # 0) 42. Communication with the vehicle control unit 4 to return the settings such as brake assist and engine control to the normal operation state, and further, the register data saved earlier from the SDRAM 8 to the register set (100) of the display controller 40 and the audio controller 41 (Time t4), the priority control register 100C of the display controller 40 and the audio controller 41 is changed to a setting for giving priority to the CPU # 1 (time t5), and based on the navigation processing by the central processing unit (CPU # 1) 11 Navigation image table A and music playback to resume. The central processing unit (CPU # 0) 10 performs image recognition processing in parallel with this to prepare for the next danger detection.

  As described above, when a plurality of address mappings are physically performed for one register set, the central processing unit (CPU # 1) 11 on which priority use is denied due to the register set setting change causes an access error. However, by saving and restoring the register set data in accordance with the setting change of the priority control register 100C, it is possible to easily resume the original display control and sound reproduction operations.

  FIG. 10 shows another example of resource units that can be shared resources of the central processing units 10 and 11. Here, a configuration when a physically different register set is provided for each address mapping is shown. For example, the display controller 40 is taken as an example. Register interfaces 110 and 111 are separately provided for the central processing unit (CPU # 0) 10 and the central processing unit (CPU # 1) 11, and a selector 112 is disposed between the display control circuit 71 and the register interfaces 110 and 111. Is done. The register interface circuit 110 includes a register set 100A, and the register interface circuit 111 includes a register set 100B and a priority control register 100C.

  FIG. 11 shows a specific example of the register interface 110 for CPU # 1. The register interface 110 includes an address decoder 120, a register write control circuit 121 as an access control circuit for the register set 100A, and a register read control circuit 122. The address decoder 120 includes decoding logic for mapping the register set 100A to the addresses F0000h to F07FFh in FIG. The address decoder 120 decodes the input address signal according to the decoding logic to generate a selection signal for the register included in the register set 100A. The register write control circuit 121 and the register read control circuit 122 receive the register selection signal output from the address decoder 120. When the write operation is instructed by the read / write signal RW, the register write control circuit 121 selects the register. The register write data is written to the register set 100A according to the signal, and when the read operation is instructed by the read / write signal RW, the register read control circuit 122 reads the register read data from the register set 100A according to the register selection signal.

  FIG. 12 shows a specific example of the register interface 111 for CPU # 0. The register interface 111 includes an address decoder 130, a register set control circuit 100A, a register write control circuit 131 as an access control circuit for the priority control register 100C, and a register read control circuit 132. The address decoder 130 includes decoding logic for mapping the register set 100B and the priority control register 100C to the addresses F0800h to F0FFFh in FIG. The address decoder 130 decodes the input address signal according to the decoding logic to generate a register selection signal included in the register set 100B and a register selection signal of the priority control register 100C. The register write control circuit 131 and the register read control circuit 132 receive the register selection signal output from the address decoder 130. When the write operation is instructed by the read / write signal RW, the register write control circuit 131 selects the register. The register write data is written in the register set 100B or the priority control register 10C according to the signal, and when the read operation is instructed by the read / write signal RW, the register read control circuit 132 follows the register selection signal according to the register selection signal. Read data from 100C. The control data set in the priority control register 10C is supplied to the selector 112. When the priority control data S1 set in the priority control register 100C indicates CPU # 0, the selector 112 selects a state in which the register set 100B of the register interface 111 is connected to the display control circuit 71, and the priority control register 100C When the priority control data S1 set to indicates CPU # 1, a state in which the register set 100A of the register interface 110 is connected to the display control circuit 71 is selected. The logical sum circuit 113 of FIG. 10 forms a logical sum signal of the output of the register read control circuit 122 and the output of the register read control circuit 132.

  Although not specifically shown, the audio controller 41 can be configured in the same manner.

  As a result, the access to the specific resource units 40 and 41 becomes the subject of access by register setting for the priority control register 100C different from the basic domain separation control by the access management circuits 20 and 21 according to the setting of the domain setting register 65. A central processing unit can be selected. The selection range is limited to the range of the central processing units 10 and 11 that are permitted to be accessed as shared resources by domain separation by the domain setting register 65. Changing the setting of the priority control register 100C has no effect on the other domain separation states. In addition, the setting of the priority control register 100C can be changed by using only one central processing unit 10. Therefore, a part of the resources 40 and 41 can be shared by the plurality of central processing units 10 and 11 while maintaining the reliability by domain separation of the entire microcomputer 1. In addition, since each of the plurality of central processing units 10 and 11 that are recognized as shared resources has register sets 100A and 100B as physical circuits, the circuit scale becomes larger than in the case of FIG. In domain separation, access to the register set by a central processing unit that is not blocked by the priority control register 100C but is not permitted to access does not cause an error.

  FIG. 13 illustrates an operation flow when the control system and the information system are controlled using the setting change of the priority control register by the microcomputer 1 adopting the configuration of FIG. The basic operating conditions are the same as in FIG. Here, since the display controller 40 and the audio controller 41 include the register sets 100A and 100B as physically separate units for the central processing units 10 and 11, the save processing after the time t2 and the time t4 described with reference to FIG. No return processing is required. Therefore, when the central processing unit (CPU # 0) 10 performs display control of a warning message, the central processing unit (CPU # 1) 11 performs data for the register set 100A of the display controller 40 and the audio controller 41 for navigation processing. The set is performed effectively. However, the data set is not reflected in the display or music playback operation.

  Although the invention made by the present inventor has been specifically described based on the embodiments, it is needless to say that the present invention is not limited thereto and can be variously modified without departing from the gist thereof.

  For example, the number of central processing units is not limited to two, and there may be more, and the central processing unit is not only a basic function for instruction execution control but also a core unit including an accelerator, work RAM, and the like. Also good. The access management circuit is illustrated as a configuration distributed for each resource unit, but is not limited thereto, and the logical configuration may be centrally arranged. The function and number of resource units, bus configuration, and the like can be changed as appropriate. The semiconductor data processing apparatus is not limited to a one-chip semiconductor integrated circuit, and may be a module device that is multi-chip and resin-sealed in one package. The data processing system to which the semiconductor data processing apparatus according to the present invention is applied is not limited to a car navigation system, but can be applied to various consumer electronic devices such as televisions, image recording / reproducing apparatuses, telephones, printers, and industrial control devices. Can be widely applied. When applied to vehicles, it is not limited to automobiles, and can be applied to transportation such as trains and ships.

1 Microcomputer (MCU)
2 Liquid crystal display 3 Audio amplifier 4 Vehicle control unit 5 Video camera 7 TV tuner 8 Memory such as DDR SDRAM 10, 11 Central processing unit (CPU # 0, CPU # 1)
20 to 31 Access management circuit (ACCSC # 0 to ACCSC # 11)
40 Display Controller 41 Audio Controller 42, 43 Serial Communication Interface Controller 44, 45 Timer (TMR # 0, TMR # 1)
46 SDRAM controller 47, 48 Direct memory access controller 49, 50 Video input circuit (VIN # 0, VIN # 1)
51 Image Recognition Processing Circuit 65 Domain Setting Register 70 Register Interface 71 Display Control Circuit 80, 81 Address Decoder 82 Decoder Output Selection Circuit 83 Register Write Control Circuit 84 Register Read Control Circuit 85 Register Write Control Circuit 86 Register Read Control Circuit 100C Priority Control Register 100 register set 100B register set 100A register set WR read / write signal 110, 111 register interface 112 selector 120 address decoder 120
121 Register Write Control Circuit 122 Register Read Control Circuit 130 Address Decoder 131 Register Write Control Circuit 132 Register Read Control Circuit

Claims (3)

A navigation system comprising a semiconductor data processing device, a display controlled by the semiconductor data processing device, and an audio amplifier for inputting an audio signal output from the semiconductor data processing device,
The semiconductor data processing apparatus comprises:
A plurality of central processing units;
An internal bus to which the plurality of central processing units are connected;
A resource unit that is made available to the plurality of central processing units via the internal bus;
An access management circuit for managing access of the resource unit by the plurality of central processing units,
The plurality of central processing units include a first central processing unit that uses the resource unit under management by a first operating system and the resource under management by a second operating system different from the first operating system. A second central processing unit using the unit,
The access management circuit controls permission and prohibition of access to the resource unit by the plurality of central processing units according to a setting state of a domain setting register,
Among the resource units, a display controller and audio that outputs the audio signal as a part of resource units recognized as shared resources between the first central processing unit and the second central processing unit by the access management circuit Have a controller,
The display controller has a first priority control register in which priority control data can be written by the first central processing unit and writing of priority control data by other central processing units is prohibited, and writing to the first priority control register. A first control circuit that performs control to allow access by the central processing unit specified by the prioritized priority control data in preference to access by other central processing units,
The display controller has a first register set used for processing of the display controller,
The audio controller has a second priority control register in which priority control data can be written by the first central processing unit, and writing of priority control data by other central processing units is prohibited, and writing to the second priority control register. A second control circuit that performs control to permit the access by the central processing unit specified by the priority control data that has been entered in preference to the access by other central processing units,
The audio controller has a second register set used for processing of the audio controller;
Said first control circuit includes a plurality of first address decoder mapping the first register set for each central processing unit is recognized to be a shared resource by the access management circuit to a different address regions, the plurality a first decoder output selection circuit to enable the first decode signal of the first address decoder corresponding to the central processing apparatus specified by the priority control data among the plurality of first decoding signals of the first address decoder, the first 1 based on the output signal selected by the decoder output selection circuit possess a first register access control circuit controls access to registers of the first register set,
The second control circuit includes a plurality of second address decoders that map the second register set to different address areas for each central processing unit that is recognized as a shared resource by the access management circuit; A second decoder output selection circuit for validating the second decode signal of the second address decoder corresponding to the central processing unit specified by the priority control data among the plurality of second decode signals of the second address decoder; A second register access control circuit that controls access to the registers of the second register set based on an output signal selected by a decoder output selection circuit;
Navigation system. A video camera for supplying a video signal to the semiconductor data processing apparatus;
The semiconductor data processing apparatus further includes a video signal input circuit for inputting the video signal, and an image recognition processing circuit for performing image processing for image recognition based on the video signal input from the video signal input circuit. ,
The first central processing unit performs image recognition based on processing data from the image recognition processing circuit, instructs the display controller to display a warning on the display according to an image recognition result, and instructs the audio controller to display the audio The navigation system according to claim 1, wherein an instruction to generate a warning sound to the amplifier is given. A vehicle control unit that receives the output of the semiconductor data processing device;
The semiconductor data processing apparatus further includes an external communication interface controller that outputs control data to the vehicle control unit,
The first central processing unit outputs the warning display data from the display controller to the display, instructs the audio controller to generate a warning voice to the audio amplifier, and the external communication interface controller. The navigation system according to claim 2, wherein control data for coping with the warning is output from the vehicle control unit to the vehicle control unit.

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