Datasheet

Section 22 Flash Memory
Rev. 3.00 Sep. 28, 2009 Page 726 of 910
REJ09B0350-0300
Error protection is canceled by a reset. Note that the reset should be released after the reset input
period of at least 100μs has passed. Since high voltages are applied during programming/erasing
of the flash memory, some voltage may remain after the error protection state has been entered.
For this reason, it is necessary to reduce the risk of damaging the flash memory by extending the
reset input period so that the charge is released.
The state-transition diagram in figure 22.16 shows transitions to and from the error protection
state.
Reset
(hardware protection)
Programming/erasing
mode
Error-protection mode
Error-protection mode
(software standby)
Read disabled
Programming/erasing enabled
FLER = 0
Read disabled
Programming/erasing disabled
FLER = 0
Read enabled
Programming/erasing disabled
FLER = 1
Read disabled
Programming/erasing disabled
FLER = 1
RES = 0
Error occurrence
Error occurred
(Software standby)
R
ES
= 0
Software standby mode
Cancel
software standby mode
RES = 0
Programming/erasing interface
register is in its initial state.
Programming/erasing interface
register is in its initial state.
Figure 22.16 Transitions to Error Protection State