HD64F2145 Datasheet, PDF (637/829 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

23.7.2 User Program Mode
On-board programming/erasing of an individual flash memory block can also be performed in user
program mode by branching to a user program/erase control program. The user must set branching
conditions and provide on-board means of supplying programming data. The flash memory must
contain the user program/erase control program or a program which provides the user
program/erase control program from external memory. Because the flash memory itself cannot be
read during programming/erasing, transfer the user program/erase control program to on-chip
RAM, as like in boot mode. Figure 23.10 shows a sample procedure for programming/erasing in
user program mode. Prepare a user program/erase control program in accordance with the
description in section 23.8, Flash Memory Programming/Erasing.
Reset-start
No
Program/erase?
Yes
Transfer user program/
erase control program to RAM
Branch to flash memory
application program
Branch to user program/
erase control program in RAM
Execute user program/erase control
program (flash memory rewrite)
Branch to flash memory
application program
Figure 23.10 Programming/Erasing Flowchart Example in User Program Mode
Rev. 2.0, 08/02, page 597 of 788