D12320VF25V Datasheet, PDF (609/1146 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

• User program mode
1. Initial state
(1) The FWE assessment program that confirms
that the FWE pin has been driven high, and (2)
the program that will transfer the programming/
erase control program to on-chip RAM should be
written into the flash memory by the user
beforehand. (3) The programming/erase control
program should be prepared in the host or in the
flash memory.
Host
Programming/
erase control program
New application
program
Chip
Boot program
Flash memory
FWE assessment
program
Transfer program
SCI
RAM
Application program
(old version)
Section 17 ROM
2. Programming/erase control program transfer
When the FWE pin is driven high, user software
confirms this fact, executes the transfer program
in the flash memory, and transfers the
programming/erase control program to RAM.
Host
New application
program
Chip
Boot program
Flash memory
FWE assessment
program
Transfer program
Application program
(old version)
SCI
RAM
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.
Host
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
New application
program
Chip
Boot program
Flash memory
FWE assessment
program
Transfer program
Flash memory
erase
SCI
RAM
Programming/
erase control program
Chip
Boot program
Flash memory
FWE assessment
program
Transfer program
New application
program
SCI
RAM
Programming/
erase control program
Program execution state
Figure 17.5 User Program Mode (Example)
Rev.7.00 Feb. 14, 2007 page 575 of 1108
REJ09B0089-0700