HD64F3028F25 Datasheet, PDF (618/925 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

18.4.2 On-Board Programming Modes
Example of Boot Mode Operation
1. Initial state
The old program version or data remains
written in the flash memory. The user should
prepare the programming control program and
new application program beforehand in the
host.
Host
Programming control
program
New application
program
H8/3028F-ZTAT
Boot program
Flash memory
SCI
RAM
Application
program
(old version)
2. Programming control program transfer
When boot mode is entered, the boot program
in the H8/3028F-ZTAT (originally incorporated
in the chip) is started and the programming
control program in the host is transferred to
RAM via SCI communication. The boot
program required for flash memory erasing is
automatically transferred to the RAM boot
program area.
Host
New application
program
H8/3028F-ZTAT
Boot program
Flash memory
SCI
RAM
Application
program
(old version)
Boot program area
Programming control
program
3. Flash memory initialization
The erase program in the boot program area
(in RAM) is executed, and the flash memory is
initialized (to H'FF). In boot mode, total flash
memory erasure is performed, without regard
to blocks.
Host
New application
program
H8/3028F-ZTAT
Boot program
Flash memory
SCI
RAM
Flash memory
prewrite-erase
Boot program area
Programming control
program
4. Writing new application program
The programming control program transferred
from the host to RAM is executed, and the new
application program in the host is written into
the flash memory.
Host
H8/3028F-ZTAT
Boot program
Flash memory
New application
program
SCI
RAM
Boot program area
Programming control
program
Rev. 2.00, 09/03, page 586 of 890
Program execution state