Figure 24.4 User Program Mode (Example) - Renesas H8S/2158 User Manual

1. Initial state
(1) The program that will transfer the programming/erase
control program from flash memory to on-chip RAM
should be written into the flash memory by the user
beforehand.
(2) The programming/erase control program should be
prepared in the host or in the flash memory.
<Host>
Programming/
erase control program
New
application program
<This LSI>
Boot program
<Flash memory>
Transfer program
Application
program
(old version)
3. Flash memory initialization
The programming/erase program in RAM is executed, and
the flash memory is initialized (to H'FF). Erasing can be
performed in block units, but not in byte units.
<Host>
New
application program
<This LSI>
Boot program
<Flash memory>
Transfer program
Flash memory
erase
SCI
<RAM>
SCI
<RAM>
Programming/
erase control program

Figure 24.4 User Program Mode (Example)

2. Programming/erase control program transfer
The transfer program in the flash memory is executed and
the programming/erase control program is transferred to RAM.
<Host>
New
application program
<This LSI>
Boot program
<Flash memory>
Transfer program
Application
program
(old version)
4. Writing new application program
Next, the new application program in the host is written into
the erased flash memory blocks. Do not write to unerased
blocks.
<Host>
<This LSI>
Boot program
<Flash memory>
Transfer program
New
application
program
Rev. 3.00 Jan 25, 2006 page 721 of 872
Section 24 ROM
SCI
<RAM>
Programming/
erase control program
SCI
<RAM>
Programming/
erase control program
Program execution state
REJ09B0286-0300