437
User Program Mode (Example)
Flash memory
H8/3022
RAM
Host
Programming/
erase control program
SCI
Boot program
New application
program
Flash memory
H8/3022
RAM
Host
SCI
New application
program
Flash memory
H8/3022
RAM
Host
SCI
Flash memory
erase
Boot program
New application
program
Flash memory
H8/3022
Program execution state
RAM
Host
SCI
Boot program
!
Boot program
FWE assessment
program
Application program
(old version)
,
New application
program
1. Initial state
The FWE assessment program that confirms that
user program mode has been entered, and the
program that will transfer the programming/erase
control program from flash memory to on-chip
RAM should be written into the flash memory by
the user beforehand. The programming/erase
control program should be prepared in the host or
in the flash memory.
2. Programming/erase control program transfer
When user program mode is entered, user
software confirms this fact, executes transfer
program in the flash memory, and transfers the
programming/erase control program to RAM.
3. Flash memory initialization
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.
4. Writing new application program
Next, the new application program in the host is
written into the erased flash memory blocks. Do
not write to unerased blocks.
Programming/
erase control program
Programming/
erase control program
Programming/
erase control program
Transfer program
Application program
(old version)
Transfer program
FWE assessment
program
FWE assessment
program
Transfer program
FWE assessment
program
Transfer program