Datasheet

Section 7 ROM
Page 228 of 982 REJ09B0465-0300 Rev. 3.00
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
7.7 Protection
Three modes are available to protect the flash memory against reading, programming, and erasing:
software protection, lock-bit protection, and protection to restrict access in programmer mode and
boot mode.
7.7.1 Software Protection
Software commands can be disabled by clearing the FMCMDEN bit in the flash memory control
register (FLMCR1) through software. In this state, no software commands are executed even if
input.
Data flash areas can be protected in block units by using the flash memory data flash protect
register (DFPR). Setting bits DFPR1 and DFPR0 in DFPR to 1 places all the data flash areas in
protect mode.
7.7.2 Lock-Bit Protection
The programming/erasure commands can be disabled by programming the lock bits using the
lock-bit program command. In this state, the erasure/programming commands are not executed
even if input. This prevents flash memory from being erroneously erased or programmed due to
CPU runaway.
The protection function can be temporarily disabled by setting the FMLBD bit in FLMCR1 to 1.
To clear the lock bit, erase the specified block. Note that lock bits are unavailable in data flash
areas.