SH7059 Datasheet, PDF (769/1042 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

24. ROM (SH7058S)
24.6 Protection
There are three kinds of flash memory program/erase protection: hardware, software, and error protection.
24.6.1 Hardware Protection
Programming and erasing of flash memory is forcibly disabled or suspended by hardware protection. In this state by the
FWE pin, the downloading of an on-chip program and initialization of the flash memory 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 FPFR parameter.
Table 24.9 Hardware Protection
Item
FWE-pin protection
Reset/standby protection
Description
The input of a low-level signal on the FWE pin
clears the FWE bit of FCCS and the LSI
enters a programming/erasing-protected state.
• A power-on reset (including a power-on
reset by the WDT) and entry to standby
mode initializes the programming/erasing
interface registers and the LSI enters a
programming/erasing-protected state.
• Resetting by means of the RES pin after
power is initially supplied will not make the
LSI enter the reset state unless the RES
pin is held low until oscillation has
stabilized. 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. If the LSI is
reset during programming or erasure, data
in the flash memory is not guaranteed. In
this case, execute erasure and then
execute programming again.
Function to be Protected
Download
Programming/
Erasure
—
O
O
O
24.6.2 Software Protection
Software protection is set up in any of three ways: by disabling the downloading of on-chip programs for programming
and erasing, by means of a key code, and by the RAM emulation register (RAMER).
Rev.3.00 Mar. 12, 2008 Page 679 of 948
REJ09B0177-0300