
Section 6 ROM
Rev. 6.00 Sep 12, 2006 page 125 of 526
REJ09B0326-0600
Boot mode can be exited by driving the reset pin low, then releasing 12 V application to the
TEST pin and FV
PP
pin at least 10 system clock cycles later, and setting the TEST pin to V
SS
to
release the reset.
However, external pin settings must not be changed during boot mode execution.
Note that the boot mode state is not maintained if 12 V application to the TEST pin is released
while in boot mode.
Also, if a watchdog timer reset occurs in this boot mode state, the built-in boot program will be
restarted without clearing the MCU’s internal mode state.
7. If the TEST pin input level is changed (e.g. from 0 V to 5 V to 12 V) during a reset (while a
low level is being input at the
RES
pin), port states will change as a result of the change of
MCU operating mode. Therefore, care must be taken to make pin settings to prevent these pins
from becoming output signal pins during a reset, and to prevent collision with signals outside
the MCU.
8. Regarding 12 V application to the FV
PP
and TEST pins, insure that peak overshoot does not
exceed the maximum rating of 13 V.
Also, be sure to connect bypass capacitors to the FV
PP
and TEST pins.
Note: * For further information on V
PP
application, release, and cut-off, see note 5 in section
6.9, Flash Memory Programming and Erasing Precautions.
6.6.2
User Program Mode
When set to user program mode, the H8/3644F, H8/3643F, or H8/3642AF can program and erase
its flash memory by executing a user program. Therefore, on-board reprogramming of the on-chip
flash memory can be carried out by providing on-board means of supplying V
PP
and programming
data, and storing an on-board reprogramming program in part of the program area.
User program mode is selected by applying 12 V to the FV
PP
pin when flash memory is not being
accessed, during a reset or after confirming that a reset has been performed properly (after the
reset is released).
The flash memory cannot be read while being programmed or erased, so the on-board
reprogramming program or flash memory reprogramming routine should be transferred to the
RAM area, and on-board reprogramming executed in that area.
Summary of Contents for F-ZTAT H8/3642A Series
Page 6: ...Rev 6 00 Sep 12 2006 page iv of xx ...
Page 8: ...Rev 6 00 Sep 12 2006 page vi of xx ...
Page 22: ...Rev 6 00 Sep 12 2006 page xx of xx ...
Page 124: ...Section 5 Power Down Modes Rev 6 00 Sep 12 2006 page 102 of 526 REJ09B0326 0600 ...
Page 188: ...Section 6 ROM Rev 6 00 Sep 12 2006 page 166 of 526 REJ09B0326 0600 ...
Page 190: ...Section 7 RAM Rev 6 00 Sep 12 2006 page 168 of 526 REJ09B0326 0600 ...
Page 298: ...Section 9 Timers Rev 6 00 Sep 12 2006 page 276 of 526 REJ09B0326 0600 ...
Page 378: ...Section 12 A D Converter Rev 6 00 Sep 12 2006 page 356 of 526 REJ09B0326 0600 ...
Page 446: ...Section 13 Electrical Characteristics Rev 6 00 Sep 12 2006 page 424 of 526 REJ09B0326 0600 ...