| 摘要 |
<p>PROBLEM TO BE SOLVED: To surely rewrite a non-volatile memory by surely and simply applying a rewriting voltage within the range of standard to a nonvolatile memory mounted in an electronic device. SOLUTION: This system 6 comprises a ECU 2 provided with a flash ROM 24 being electrically rewritable data and a memory rewriting device 4 which is connected to the ECU 2, outputs rewriting voltage Vfp required for rewriting the flash ROM 24, while sends rewriting information for rewriting the flash ROM 24 to the ECU 2. In this case, on the ECU 2 side, rewriting voltage Vfp actually applied to the flash ROM 24 is detected by an A/D converter 16, an adjusting signal is sent to a memory rewriting device 4 so that the value is in a standard range, and the memory rewriting device 4 adjusts an output value of the rewriting voltage Vfp in accordance with the adjusting signal fro the ECU 2. Consequently, appropriate rewriting voltage can be simply applied to the flash ROM 24.</p> |
