NEC V850ES/F 3-L Series User Manual page 292

Chapter 8
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(5)
Table 8-2
Function Functional outline
Block erase Erasure of single blocks impossible.
command prohibit Once block erase protection is enabled,
disable is only possible after chip erase.
Chip erase Erasure of the entire flash (including the extra
command prohibit area) or single blocks impossible.
Once chip erase protection is enabled, all
protection flag settings can not be changed
any more.
Program command Erasure and rewrite of single blocks
prohibit impossible.
Once write protection is enabled, disable is
only possible after chip erase.
Read command Read-out of any flash content impossible.
prohibit Once read protection is enabled, disable is
only possible after chip erase.
Rewriting boot Erasure (by block or chip erase) or writing of
block cluster the boot block cluster impossible.
prohibit Once rewrite protection of the boot block
cluster is enabled, it can not be disabled any
more.
292
Read-out protection flag
Set this flag to disable the feature that allows reading back the flash memory
via external flash programmer interfaces.
No flash content can be read out.
This flag does not affect the self-programming interface.
In self-programming mode read-out of flash memory content is further on
possible.
Boot block cluster protection flag
Set this flag to disable erasure and rewrite of the boot block cluster.
The boot block cluster can not be manipulated in any way (no erase/write).
This applies in serial and self-programming mode.
Once this flag is set, it is impossible to reset this flag. Thus the boot block
cluster content can not be changed any more.
For the explanation of the boot block cluster refer to "Secure self-programming
(boot cluster swapping)" on page 279.
All protection flags are reset after shipment of the device, thus no protection is
enabled at all.
Once a protection flag has been set, i.e. the protection is effective, it can not be
reset by any means, except after a chip erase, which erases the entire flash
memory including the extra area.
Consequently without prior chip erase the protection level can only be
increased, but not decreased.
Protection functions overview
User's Manual U18743EE1V2UM00
Data Protection and Security
Applicable
(√: applies, ×: doesn't apply)
Serial
Self-programming
programming
√
√
√
√
√
×
×
×
×
√