RL78/G1P
CHAPTER 23 FLASH MEMORY
R01UH0895EJ0100 Rev.1.00
685
Nov 29, 2019
23.6 Security Settings
The RL78/G1P supports a security function that prohibits rewriting the user program written to the internal flash
memory, so that the program cannot be changed by an unauthorized person.
The operations shown below can be performed using the Security Set command.
Disabling block erase
Execution of the block erase command for a specific block in the flash memory is prohibited during on-board/off-
board programming. However, blocks can be erased by means of self-programming.
Disabling write
Execution of the write command for entire blocks in the flash memory is prohibited during on-board/off-board
programming. However, blocks can be written by means of self-programming.
After the security settings are specified, releasing the security settings by the Security Release command is enabled
by a reset.
After the security settings are specified, releasing the security settings by the Security Release command is enabled by
a reset.
The block erase and write commands are enabled by the default setting when the flash memory is shipped. Security
can be set by on-board/off-board programming and self-programming. Each security setting can be used in combination.
Table 23-11 shows the relationship between the erase and write commands when the RL78/G1P security function is
enabled.
Caution The security function of the flash programmer does not support self-programming.
Remark
To prohibit writing and erasing during self-programming, use the flash sealed window function (see
23.7.1
for
detail).