NEC V850ES/F 3-L Series User Manual page 282

32-bit single-chip microcontroller

Table of Contents

Figure 7-16 on page 282 illustrates an example with following settings:

• number of boot blocks: 2 (boot block cluster contains 2 blocks), thus the

active boot block cluster comprises

– if boot_flag: blocks 0and 1

– if not(boot_flag): blocks 4 and 5

• active boot swap clusters comprises

– if boot_flag: blocks 0 to 3

– if not(boot_flag): blocks 4 to 7

Boot cluster swapping function

To prohibit rewriting of the boot blocks, the boot block cluster protection flag

can be set during flash memory programming. When this flag is set, the blocks

of the active boot block cluster can neither be erased nor written. Boot cluster

swapping is impossible as well.

Note that only the blocks of the active boot block cluster are protected. In the

example according to Figure 7-16 on page 282, for instance, blocks 0 and 1

would be prohibited, while blocks 2 and 3 could still be erased and written.

Once the boot block cluster protection has been activated, it can never be

deactivated again.

For further information concerning flash memory protection flags refer to "Data

Protection and Security" on page 289.

User's Manual U18743EE1V2UM00

Flash Memory

not(boot_flag)