Flash Memory Protection; Hardware Protection - Renesas F-ZTAT H8 Series Hardware Manual

6.6

Flash Memory Protection

There are three kinds of flash memory program/erase protection: hardware, software, and error
protection.
6.6.1

Hardware Protection

Hardware protection refers to a state in which programming/erasing of flash memory is forcibly
disabled or aborted. In this state, the settings in flash memory control registers 1 and 2 (FLMCR1,
FLMCR2) and the erase block register (EBR) are reset. (See table 6.7.)
Table 6.7 Hardware Protection
Item Description
•
FWE pin
When a low level is input to the FWE pin,
protection
FLMCR1, FLMCR2 (except the FLER bit),
and EBR are initialized, and the
program/erase-protected state is entered.*
•
Reset/standby
In a reset (including a WDT overflow reset)
protection
and in standby mode, FLMCR1, FLMCR2,
and EBR are initialized, and the program/
erase-protected state is entered.
In a reset via the RES pin, the reset state is
•
not entered unless the RES pin is held low
for a minimum of 40 ms (oscillation
stabilization time)*
case of a reset during operation, hold the
RES pin low for a minimum of 10 system
clock cycles (10φ).
Notes: 1. Two modes: program-verify and erase-verify.
2. All blocks are unerasable and block-by-block specification is not possible.
3. For details see section 6.9, Flash Memory Programming and Erasing Precautions.
4. For details see the AC characteristics in sections 15.2.3 and 16.2.3, Electrical
Characteristics.
4
after powering on. In the
Rev.3.00 Jul. 19, 2007 page 145 of 532
Functions
Program Erase
Not Not
possible possible*
3
Not Not
possible possible*
REJ09B0397-0300
6. ROM
1
Verify*
Not
2
possible
Not
2
possible