HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 774

• Manufacturer Part Number: HD6412320
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family H8S-2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 19 ROM
• User program mode
Rev.6.00 Sep. 27, 2007 Page 744 of 1268
REJ09B0220-0600
1. Initial state
3. Flash memory initialization
(1) The program that will transfer the
programming/erase control program to on-chip
RAM should be written into the flash memory by
the user beforehand. (2) The programming/erase
control program should be prepared in the host
or in the flash memory.
The programming/erase program in RAM is
executed, and the flash memory is initialized (to
H'FF). Erasing can be performed in block units,
but not in byte units.
Chip
Chip
Application program
Transfer program
Transfer program
Flash memory
Flash memory
Flash memory
Boot program
Boot program
(old version)
erase
erase control program
New application
New application
Programming/
program
program
Host
Host
Figure 19.5 User Program Mode (Example)
erase control program
Programming/
RAM
RAM
SCI
SCI
2. Programming/erase control program transfer
4. Writing new application program
Chip
Chip
Executes the transfer program in the flash
memory, and transfers the programming/erase
control program to RAM.
Next, the new application program in the host is
written into the erased flash memory blocks. Do
not write to unerased blocks.
Application program
Transfer program
Transfer program
New application
Flash memory
Flash memory
Boot program
Boot program
(old version)
program
New application
program
Host
Host
erase control program
erase control program
Programming/
Programming/
Program execution state
RAM
RAM
SCI
SCI