Nonvolatile memory writing device

A nonvolatile memory writing device wherein,

• a nonvolatile memory writing device that writes write data transmitted from a microcomputer to a nonvolatile memory is provided outside the microcomputer,
• the nonvolatile memory is a nonvolatile memory in which writing of the writing data is protected and the protection is disabled by an electric signal from the microcomputer to a write-protect terminal of the nonvolatile memory,
• when the electric signal from the microcomputer to the write-protect terminal is interrupted, the protection is disabled, and
• when the microcomputer is reset due to noise, the write-protect terminal of the nonvolatile memory is controlled to be write-protected by a decision circuit for protection/permission with noise support, and writing of the noise to the nonvolatile memory is protected.

A nonvolatile memory writing device wherein,

• a nonvolatile memory writing device that writes write data transmitted from a microcomputer to a nonvolatile memory is provided outside the microcomputer,
• the nonvolatile memory is a nonvolatile memory in which writing of the writing data is protected and the protection is disabled by an electric signal from the microcomputer to a write-protect terminal of the nonvolatile memory,
• when the electric signal from the microcomputer to the write-protect terminal is interrupted, the protection is disabled, and
• a decision circuit for protection/permission with microcomputer abnormality support is provided to control a state of the write protection and of the write-protect terminal of the nonvolatile memory and the disabled state of the protection in response to the voltage drop of the power supply of the microcomputer and the reset signal to the microcomputer.