Hitachi H8S/2199 Hardware Manual page 144

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
<This LSI>
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
<This LSI>
Boot program
<Flash memory>
Flash memory erase
<Host>
program
program
SCI
<RAM>
<Host>
program
program
SCI
<RAM>
Boot program area
Figure 7.4 Boot Mode
2. Writing control program transfer
When boot mode is entered, the boot program in
this LSI chip (originally incorporated in the chip) is
started, and 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
<This LSI>
Boot program
<Flash memory>
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>
<This LSI>
Boot program
<Flash memory>
New application
program
Rev. 1.0, 02/00, page 127 of 1141
SCI
<RAM>
Boot program area
SCI
<RAM>
Programming control
program
Program execution state