SH7050 Datasheet, PDF (629/841 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH RISC engine Family/

Section 19 ROM (256 kB Version)
19.6.2 User Program Mode
After setting FWE, the user should branch to, and execute, the previously prepared
programming/erase control program.
As the flash memory itself cannot be read while flash memory programming/erasing is being
executed, the control program that performs programming and erasing should be run in on-chip
RAM or external memory.
Use the following procedure (figure 19.6) to execute the programming control program that writes
to flash memory (when transferred to RAM).
Write FWE assessment program
1
and transfer program
FWE = 1
2
(user program mode)
3
Transfer programming/erase
control program to RAM
Execute programming/
4 ^{erase control program in RAM}
(flash memory rewriting)
Execute user application
5
program
Figure 19.6 User Program Mode Execution Procedure
Note: When programming and erasing, start the watchdog timer so that measures can be taken to
prevent program runaway, etc. Memory cells may not operate normally if
overprogrammed or overerased due to program runaway.
Rev. 5.00 Jan 06, 2006 page 609 of 818
REJ09B0273-0500