DF2211NP24V Renesas Technology / Hitachi Semiconductor, DF2211NP24V Datasheet - Page 637

• Manufacturer Part Number: DF2211NP24V
• Description: H8S/2200 Series, 2212 Group, USB, RTC, HSS TNP-64B; Vcc= 2.7 to 3.6 volts, Temp= -20 to 75 C; Package: PVQN0064LB-A
• Manufacturer: Renesas Technology / Hitachi Semiconductor

17.9
There are three kinds of flash memory program/erase protection: hardware protection, software
protection, and error protection.
17.9.1
Hardware protection refers to a state in which programming/erasing of flash memory is forcibly
disabled or aborted because of a transition to reset or standby mode. Flash memory control
register 1 (FLMCR1), flash memory control register 2 (FLMCR2), erase block register 1 (EBR1),
and erase block register 2 (EBR2) are initialized. In a reset via the RES pin, the reset state is not
entered unless the RES pin is held low until oscillation stabilizes after powering on. In the case of
a reset during operation, hold the RES pin low for the RES pulse width specified in the AC
Characteristics section.
17.9.2
Software protection can be implemented against programming/erasing of all flash memory blocks
by clearing the SWE1 bit in FLMCR1. When software protection is in effect, setting the P1 or E1
bit in FLMCR1 does not cause a transition to program mode or erase mode. By setting the erase
block register 1 (EBR1), and erase block register 2 (EBR2), erase protection can be set for
individual blocks. When EBR1 and EBR2 are set to H'00, erase protection is set for all blocks.
17.9.3
In error protection, an error is detected when the CPU's runaway occurs during flash memory
programming/erasing, or operation is not performed in accordance with the program/erase
algorithm, and the program/erase operation is aborted. Aborting the program/erase operation
prevents damage to the flash memory due to overprogramming or overerasing.
When the following errors are detected during programming/erasing of flash memory, the FLER
bit in FLMCR2 is set to 1, and the error protection state is entered.
Setting Conditions of FLER Bit (Erase Protection)
• When the flash memory of the relevant address area is read during programming/erasing
• Immediately after exception handling (excluding a reset) during programming/erasing
• When a SLEEP instruction is executed during programming/erasing
• When the CPU releases the bus mastership to the DMAC during programming/erasing
(including vector read and instruction fetch)
Program/Erase Protection
Hardware Protection
Software Protection
Error Protection
Rev.7.00 Dec. 24, 2008 Page 583 of 698
REJ09B0074-0700