| 摘要 |
<p>PURPOSE:To provide a semiconductor nonvolatile memory without unrevealing data even when it is irradiated by an alpha-ray and is in a high temperature state. CONSTITUTION:The semiconductor memory 1 is provided with a first read only memory block 110 writable electrically only once, a second memory block 120 writable/erasable electrically, a control block 130 controlling input/output and write/erasure voltage in the first and the second memory blocks and a timer 140 deciding a time when information is written to the first and the second memory blocks.</p> |
