h8s-2161b Renesas Electronics Corporation., h8s-2161b Datasheet - Page 660

• Manufacturer Part Number: h8s-2161b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 23 ROM
Rev. 3.00 Mar 21, 2006 page 606 of 788
REJ09B0300-0300
3. Flash memory initialization
1. Initial state
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.
The flash memory is erased at shipment.
The following describes how to write over
an old-version application program or data in
the flash memory. The user should prepare
the programming control program and
new application program beforehand in the host.
<This LSI>
<This LSI>
<Flash memory>
<Flash memory>
Flash memory
Boot program
Boot program
(old version)
Application
program
erase
application program
application program
control program
Programming
<Host>
<Host>
New
New
Boot program area
control program
Programming
<RAM>
<RAM>
SCI
SCI
Figure 23.3 Boot Mode
2. SCI communication check
4. Writing new application program
<This LSI>
<This LSI>
When boot mode is entered, the boot program in
this LSI (originally incorporated in the chip) is started
and SCI communication is checked. Then 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 via SCI communication is executed,
and the new application program in the host is written
into the flash memory.
<Flash memory>
<Flash memory>
Boot program
Boot program
(old version)
Application
application
program
program
New
application program
<Host>
<Host>
New
Boot program area
Boot program area
control program
control program
Programming
Programming
Program execution state
<RAM>
<RAM>
SCI
SCI