SH7147 Datasheet, PDF (876/1108 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH™ RISC engine Family

Section 20 Flash Memory
The difference between the programming procedures in user program mode and user boot mode is
whether the MAT is switched or not as shown in figure 20.14.
In user boot mode, the user boot MAT can be seen in the flash memory space with the user MAT
hidden in the background. The user MAT and user boot MAT are switched only while the user
MAT is being programmed. Because the user boot MAT is hidden while the user MAT is being
programmed, the procedure program must be located in an area other than flash memory. After
programming finishes, switch the MATs again to return to the first state.
MAT switchover 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 completely 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 20.8.1, 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, user
MAT, and external space) is shown in section 20.9.2, Areas for Storage of the Procedural Program
and Data for Programming.
Rev. 3.00 Oct. 06, 2008 Page 852 of 1080
REJ09B0230-0300