h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 700

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 20 ROM
20.2.3
Boot Mode
Rev. 5.00 Sep 22, 2005 page 674 of 1136
REJ09B0257-0500
1. Initial state
3. Flash memory initialization
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.
LSI
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.
LSI
On-Board Programming Modes
Application program
preprogramming
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
2. Programming control program transfer
4. Writing new application program
LSI
LSI
When boot mode is entered, the boot program in
the LSI (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