| 摘要 |
An electronic postage meter includes a memory protection circuit. The memory protection circuit prevents the inadvertent writing of spurious data into memory locations in the nonvolatile memory during a power down cycle. The memory protection circuit works in conjection with a WRITE voltage terminal associated with the nonvolatile memory. Means couple a first voltage source providing a predetermined polarity voltage to the WRITE voltage terminal when a predetermined power condition exists such that the nonvolatile memory is enabled to have data written into memory locations. When the predetermined power condition does not exist, the means utilize a second different voltage source to change the voltage level at the WRITE voltage terminal to insure that data is not written into the memory locations.
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