Renesas H8/3067 Series User Manual page 646

Section 18 ROM
On-Board Programming Modes
• Boot mode
1. Initial state
The flash memory is in the erased state when the
device is shipped. The description here applies to
the case where the old program version or data
is being rewritten. The user should prepare the
programming control program and new
application program beforehand in the host.
Programming control
New application
H8/3067 Group chip
Boot program
Flash memory
Application program
(old version)
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, entire flash
memory erasure is performed, without regard to
blocks.
Programming control
New application
H8/3067 Group chip
Boot program
Flash memory
Flash memory
erase
Rev. 4.00 Jan 26, 2006 page 622 of 938
REJ09B0276-0400
Host
program
program
SCI
RAM
Host
program
program
SCI
RAM
Boot program area
Figure 18.3 Boot Mode
2. Programming control program transfer
When boot mode is entered, the boot program in
the H8/3067 Group chip (originally incorporated
in the chip) is started, an SCI communication
check is carried out, and the boot program
required for flash memory erasing is
automatically transferred to the RAM boot
program area.
Host
Programming control
program
New application
program
H8/3067 Group chip
Boot program
Flash memory
Boot program area
Application program
(old version)
4. Writing new application program
The programming control program transferred
from the host to RAM by SCI communication is
executed, and the new application program in the
host is written into the flash memory.
Host
H8/3067 Group chip
Boot program
Flash memory
New application
program
SCI
RAM
SCI
RAM
Programming
control program
Program execution state