Datasheet

Section 24 Flash Memory
Rev. 2.00 Sep. 28, 2009 Page 791 of 994
REJ09B0452-0200
MAT switching is enabled by writing a specific value to FMATS. Note, however, 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, and if an interrupt occurs, from which MAT the interrupt vector is
read is undetermined. Perform MAT switching in accordance with the description in section
24.10, Switching between User MAT and User Boot MAT.
Except for MAT switching, the programming 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 and user
MAT) is shown in section 24.8.4, Storable Areas for On-Chip Program and Program Data.
(3) User MAT Erasing in User Boot Mode
For erasing the user MAT in user boot mode, additional processing made by setting FMATS are
required: switching from user-boot-MAT selection state to user-MAT selection state, and
switching back to user-boot-MAT selection state after erasing completes.
Figure 24.15 shows the procedure for erasing the user MAT in user boot mode.