AUTOMOTIVE RECORDER
First Claim
1. An automobile recorder for recording vehicle conditions comprising:
- a one-chip data processor coupled to signal lines transmitting functional information relevant to functional parts mounted in the vehicle; and
an external memory coupled to the data processor,wherein the data processor comprises;
an input circuit which input a functional information from the signal lines;
an internal memory comprising an MRAM for temporarily storing the functional information taken in by the input circuit from the signal lines; and
a central processing unit,wherein the central processing unit performs storing control for storing the functional information into the internal memory while circulating a access address ranging from an initial address to an end address, saving control for saving the functional information from the internal memory to the external memory before being overwritten by the access address circulation, and disabling control for disabling storing of functional information by the storing control when the amount of new information being stored in the internal memory by the storing control has reached to a specified quantity in response to a certain event occurrence, andwherein the specified quantity is less than a storage capacity ranging from the initial address up to the end address.
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0 Petitions
Accused Products
Abstract
Functional information acquired before and after an event occurrence is held on an on-chip MRAM built in a data processor, thus preventing the held functional information from being falsified and erased. An automobile recorder of the present invention comprises a one-chip data processor coupled to signal lines transmitting functional information indicating vehicle conditions and an external memory. The data processor comprises an input circuit which takes input of functional information, an MRAM for temporarily storing functional information, and a central processing unit (CPU). The CPU performs wrap-around control for storing functional information into the MRAM. The CPU also performs disabling control for disabling storing of functional information when the amount of new information being stored on the MRAM by wrap-around control in response to and following a certain event occurrence has reached a specific quantity that is less than a storage capacity from the initial address to the end address. Thereby, the on-chip MRAM can hold functional information acquired before and after an event occurrence.
29 Citations
15 Claims
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1. An automobile recorder for recording vehicle conditions comprising:
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a one-chip data processor coupled to signal lines transmitting functional information relevant to functional parts mounted in the vehicle; and an external memory coupled to the data processor, wherein the data processor comprises;
an input circuit which input a functional information from the signal lines;
an internal memory comprising an MRAM for temporarily storing the functional information taken in by the input circuit from the signal lines; and
a central processing unit,wherein the central processing unit performs storing control for storing the functional information into the internal memory while circulating a access address ranging from an initial address to an end address, saving control for saving the functional information from the internal memory to the external memory before being overwritten by the access address circulation, and disabling control for disabling storing of functional information by the storing control when the amount of new information being stored in the internal memory by the storing control has reached to a specified quantity in response to a certain event occurrence, and wherein the specified quantity is less than a storage capacity ranging from the initial address up to the end address. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An automobile recorder for recording vehicle conditions comprising:
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a data processor coupled to signal lines transmitting functional information relevant to functional parts mounted in the vehicle and having an on-chip buffer memory comprising an MRAM for temporarily storing the functional information taken in from the signal lines; a working memory which is coupled to the data processor and to which the functional information held on the buffer memory is transferred; and an external storage device for storing the functional information once held on the working memory. - View Dependent Claims (11)
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12. A buffer memory system comprising:
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a first memory comprising an MRAM; a second memory comprising an MRAM into which a data held on the first memory is written and which has a larger storage capacity than the first memory; and a third memory comprising an nonvolatile memory into which a data held on the second memory is written and which has a larger storage capacity than the second memory, but can only be rewritten a significantly smaller number of times in comparison with MRAM. - View Dependent Claims (13, 14, 15)
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Specification