SH7125_08 Datasheet, PDF (631/774 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family

Section 17 Flash Memory
17.5.2 User Program Mode (Only in On-Chip 128-Kbyte and 64-Kbyte ROM Version)
The user MAT can be programmed/erased in user program mode.
Programming/erasing is executed by downloading the program in the microcomputer.
The overview flow is shown in figure 17.9.
High voltage is applied to internal flash memory during the programming/erasing processing.
Therefore, transition to reset must not be executed. Doing so may cause damage or destroy flash
memory. If reset is executed accidentally, the reset signal must be released after the reset input
period, which is longer than the normal 100 µs.
For details on the programming procedure, see the description in section 17.5.2 (2), Programming
Procedure in User Program Mode. For details on the erasing procedure, see the description in
section 17.5.2 (3), Erasing Procedure in User Program Mode.
Programming/erasing
start
When programming,
program data is prepared
1. Inputting high level to the FWE pin sets the
FWE bit to 1.
2. Programming/erasing is executed only in
the on-chip RAM.
3. After programming/erasing is finished, low level
must be input to the FWE pin for protection.
FWE = 1 ?
No
Yes
Programming/erasing
procedure program is
transferred to the on-chip
RAM and executed
Programming/erasing
end
Figure 17.9 Programming/Erasing Overview Flow
Rev. 4.00 Jul. 25, 2008 Page 611 of 750
REJ09B0243-0400