HD64F2168 Datasheet, PDF (707/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Error protection is cancelled only by a reset or by hardware-standby mode. Note that the reset
should be released after the reset period of 100 µs which is longer than normal. 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 damage to the flash memory by extending the reset period so that the charge is released.
The state-transition diagram in figure 20.16 shows transitions to and from the error-protection
state.
Program mode
Erase mode
RES = 0 or STBY = 0
Reset or hardware
standby
(Hardware protection)
Read disabled
Programming/erasing
enabled FLER = 0
Error occurrence
Er_{(rSorofotwccaurerresdtandRbEy)SS=T0BYor= 0}
Read disabled
Programming/erasing disabled
FLER = 0
RES = 0 or
STBY = 0
Program/erase interface
register is in its initial state.
Error protection mode Software-standby mode
Error-protection mode
(Software standby)
Read enabled
Programming/erasing disabled
FLER = 1
Cancel
Read disabled
programming/erasing disabled
software-standby mode
FLER = 1
Program/erase interface
register is in its initial state.
Figure 20.16 Transitions to Error-Protection State
Rev. 3.00, 03/04, page 667 of 830