Datasheet

Section 17 Flash Memory (F-ZTAT Version)
Rev.7.00 Dec. 24, 2008 Page 556 of 698
REJ09B0074-0700
Flash memory
This LSI
RAM
Host
Programming control
program
Application program
(old version)
New application
program
Flash memory
This LSI
RAM
Host
Application program
(old version)
Boot program area
New application
program
Flash memory
This LSI
RAM
Host
Flash memory
preprogramming
erase
Boot program
New application
program
Flash memory
This LSI
Program execution stat
e
RAM
Host
New application
program
Boot program
Programming control
program
1. Initial state
The old program version or data remains written
in the flash memory. The user should prepare the
programming control program and new
application program beforehand in the host.
2. Programming control program transfer
When boot mode is entered, the boot program in
this LSI (originally incorporated in the chip) is
started and the programming control program in
the host is transferred to RAM via SCI or USB
communication. The boot program required for
flash memory erasing is automatically transferred
to the RAM boot program area.
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, total flash
memory erasure is performed, without regard to
blocks.
4. Writing new application program
The programming control program transferred
from the host to RAM is executed, and the new
application program in the host is written into the
flash memory.
Programming control
program
Boot programBoot program
Boot program area Boot program area
Programming control
program
SCI
or USB
SCI
or USB
SCI
or USB
SCI
or USB
Figure 17.3 Boot Mode (Sample)