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Fiscal data recorder with protection circuit and tamper-proof seal

  • US 7,523,320 B2
  • Filed: 04/22/2003
  • Issued: 04/21/2009
  • Est. Priority Date: 04/22/2003
  • Status: Expired due to Fees
First Claim
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1. A fiscal data recorder for storing transaction related data, comprising:

  • a processing unit receiving transaction related data;

    memory communicating with said processing unit for storing said transaction related data; and

    a protection circuit acting between said processing unit and said memory, said protection circuit inhibiting electronic tampering with said memory, said processing unit commencing initialization by writing an identification pattern to the protection circuit and checking for a response; and

    wherein said protection circuit includes a store to hold data to be written to said memory and a comparator to determine whether a block in said memory to which the held data is to be written is blank, data in said store being passed to said memory only when said memory block is blank thereby preventing data stored in said memory from being overwritten; and

    wherein said protection circuit inhibits said memory from being written with blank value.

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