HD64F2145 Datasheet, PDF (621/829 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

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
SCI
<RAM>
Application
program
(old version)
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
SCI
<RAM>
Application
program
(old version)
Programming/
erase control program
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.
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>
<Host>
New
application program
<This LSI>
Boot program
<Flash memory>
SCI
<RAM>
Transfer program
Flash memory
erase
Programming/
erase control program
<This LSI>
Boot program
<Flash memory>
Transfer program
New
application
program
SCI
<RAM>
Programming/
erase control program
Program execution state
Figure 23.4 User Program Mode (Example)
Rev. 2.0, 08/02, page 581 of 788