D12320VF25IV Datasheet, PDF (847/1304 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 19 ROM
19.15.2 User Program Mode
When set to user program mode, the chip can program and erase its flash memory by executing a
user program/erase control program. Therefore, on-board reprogramming of the on-chip flash
memory can be carried out by providing on-board means of FWE control and supply of
programming data, and storing a program/erase control program in part of the program area as
necessary.
To select user program mode, select a mode that enables the on-chip flash memory (mode 6 or 7),
and apply a high level to the FWE pin. In this mode, on-chip supporting modules other than flash
memory operate as they normally would in modes 6 and 7.
The flash memory itself cannot be read while the SWE bit is set to 1 to perform programming or
erasing, so the control program that performs programming and erasing should be run in on-chip
RAM or external memory. 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 19.40 shows the procedure for executing the program/erase control program when
transferred to on-chip RAM.
Rev.6.00 Sep. 27, 2007 Page 815 of 1268
REJ09B0220-0600