Datasheet

Section 17 ROM
Rev.7.00 Feb. 14, 2007 page 575 of 1108
REJ09B0089-0700
• User program mode
Flash memory
Chip
Chip
RAM
Host
Programming/
erase control program
SCI
Boot program
New application
program
Flash memory RAM
Host
SCI
New application
program
Flash memory RAM
Host
SCI
Flash memory
erase
Boot program
New application
program
Flash memory
Program execution state
RAM
Host
SCI
Boot program
Boot program
FWE assessment
program
Application program
(old version)
New application
program
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 shou
ld 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.
2. Programming/erase control progra
m 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.
3. Fl
ash 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.
Programming/
erase control program
Programming/
erase control program
Programming/
erase control program
Transfer program
Application program
(old version)
Transfer program
FWE assessment
program
FWE assessment
program
Transfer program
FWE assessment
program
Transfer program
Chip
Chip
Figure 17.5 User Program Mode (Example)