D12320VF25V Datasheet, PDF (689/1146 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 17 ROM
While the SWE1 bit is set to 1 to perform programming or erasing for the addresses H'000000 to
H'03FFFF, this address area cannot be read. While the SWE2 bit is set to 1 to perform
programming or erasing for the addresses H'040000 to H'07FFFF, this address area cannot be
read. The control program that performs programming and erasing should be run in on-chip RAM
or flash memory except for the above address areas. When the program is located in external
memory, an instruction for programming the flash memory and the following instruction should
be located in on-chip RAM.
Figure 17.44 shows the procedure for executing the program/erase control program when
transferred to on-chip RAM.
Write transfer program (and the
program/erase control program if
necessary) beforehand
MD2, MD1, MD0 = 110, 111
Reset-start
Transfer program/erase control
program to RAM
Branch to program/erase control
program in RAM area
Execute program/erase control
program (flash memory rewriting)
Branch to flash memory application
program
Note: The watchdog timer should be activated to prevent overprogramming or overerasing
due to program runaway, etc.
Figure 17.44 User Program Mode Execution Procedure
Rev.7.00 Feb. 14, 2007 page 655 of 1108
REJ09B0089-0700