HD6412340 HITACHI [Hitachi Semiconductor], HD6412340 Datasheet - Page 566

• Manufacturer Part Number: HD6412340
• Description: H8S/2345 F-ZTAT Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

On-Board Programming Modes
554
Boot mode
1. Initial state
3. Flash memory initialization
H8S/2345 F-ZTAT chip
H8S/2345 F-ZTAT chip
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.
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.
Application program
Flash memory
Flash memory
Flash memory
Boot program
Boot program
(old version)
erase
Programming control
New application
New application
program
program
program
Host
Host
Boot program area
Programming control
program
RAM
RAM
SCI
SCI
Figure 17.9 Boot Mode
2. Programming control program transfer
4. Writing new application program
H8S/2345 F-ZTAT chip
H8S/2345 F-ZTAT chip
When boot mode is entered, the boot program in
the H8S/2345 chip (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.
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.
Application program
New application
Flash memory
Flash memory
Boot program
Boot program
(old version)
program
New application
program
Host
Host
Boot program area
Boot program area
Programming control
Programming control
Program execution state
program
program
RAM
RAM
SCI
SCI