HD64F2168 Datasheet, PDF (705/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

20.5 Protection
There are three kinds of flash memory program/erase protection: hardware, software, and error
protection.
20.5.1 Hardware Protection
Programming and erasing of flash memory is forcibly disabled or suspended by hardware
protection. In this state, the downloading of an on-chip program and initialization are possible.
However, an activated program for programming or erasure cannot program or erase locations in a
user MAT, and the error in programming/erasing is reported in the parameter FPFR.
Table 20.9 Hardware Protection
Item
FWE pin protection
Reset/standby
protection
Function to be Protected
Description
Download Program/Erase
• When a low level signal is input to the 
FWE pin, the FWE bit in FCCS is
cleared and the program/erase-
protected state is entered.
• The program/erase interface registers
are initialized in the reset state
(including a reset by the WDT) and
standby mode and the program/erase-
protected state is entered.
• The reset state will not be entered by
a reset using the RES pin unless the
RES pin is held low until oscillation
has stabilized after power is initially
supplied. In the case of a reset during
operation, hold the RES pin low for the
RES pulse width that is specified in
the section on AC characteristics
section. If a reset is input during
programming or erasure, data values
in the flash memory are not
guaranteed. In this case, execute
erasure and then execute program
again.
Rev. 3.00, 03/04, page 665 of 830