NEC PG-FP4, Руководство пользователя

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CHAPTER 4 PG-FP4 OPERATION USING GUI SOFTWARE
User’s Manual U15260EJ3V1UM
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<3> Security flag settings
The <Security flag settings> dialog box is used to specify which security function is valid.
This function is valid only when a single-power-supply flash memory microcontroller is used.
Figure 4-29. Setup Window – Security Flag Settings
[Disable Chip Erase check box]
If this check box is checked, the Erase command becomes invalid in the entire flash memory area of the
target device.
A warning message “I907 Caution: When ‘Chip Erase’ is disabled, chips can no longer be erased or
programmed!” is displayed when OK is clicked in the Device Setup Window after checking this box.
Caution Be aware that if the security flag is set in the target device, neither erasing nor writing
Note
to the device can be enabled afterward.
[Disable Block Erase check box]
If this check box is checked, the Erase command becomes invalid in all the blocks of the flash memory
selected under Operation Mode in the Standard Setup menu.
This setting is cleared by the Erase command when Chip was selected under Operation Mode.
[Disable Program check box]
If this check box is checked, the Program command becomes invalid, as does the Erase command in all the
blocks of the flash memory selected under Operation Mode in the Standard Setup menu.
The Erase command for the entire flash memory area is valid.
This setting is cleared by the Erase command when Chip was selected under the Operation Mode.
The following is the correspondence between the Erase and Program commands when the security functions
of a single-power-supply flash memory microcontroller are valid.
Erase Command for the
Entire Flash Memory Area
Erase Command for Selected
Flash Memory Blocks
Program Command
Disable Chip Erase Invalid Invalid Valid
Note
Disable Block Erase Valid Invalid Valid
Disable Program Valid Invalid Invalid
Note Since the Erase command is invalid, the data that differs from the data already written in the flash
memory cannot be written.