SH7055S Datasheet, PDF (823/1002 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7000 Series

MAT switching is enabled by writing a specific value to FMATS. However note that while the
MATs are being switched, the LSI is in an unstable state, e.g. access to a MAT is not allowed until
MAT switching is completed finished, and if an interrupt occurs, from which MAT the interrupt
vector is read from is undetermined. Perform MAT switching in accordance with the description
in section 22.8.1, Switching between User MAT and User Boot MAT.
Except for MAT switching, the erasing procedure is the same as that in user program mode.
The area that can be executed in the steps of the user procedure program (on-chip RAM, user
MAT, and external space) is shown in section 22.10.3, Storable Area for Procedure Program and
Programming Data.
22.6 Protection
There are three kinds of flash memory program/erase protection: hardware, software, and error
protection.
22.6.1 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 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.
Rev.2.0, 07/03, page 785 of 960