On-Board Programming Modes; Boot Mode - Renesas H8 Series Hardware Manual

Section 6 ROM
6.6

On-Board Programming Modes

When an on-board programming mode is selected, on-chip flash memory programming, erasing,
and verifying can be carried out. There are two on-board programming modesboot mode and
user program modeset by the mode pin (TEST) and the FV
the on-board programming modes. For information on turning V
6.9, Flash Memory Programming and Erasing Precautions.
Table 6.9 On-Board Programming Mode Selection
Mode Setting

Boot mode

User program mode
Note: * See notes 6 to 8 in section 6.6.1, Notes on Use of Boot Mode, for the timing of 12 V
application.
6.6.1 Boot Mode
When boot mode is used, a user program for flash memory programming and erasing must be
prepared beforehand in the host machine (which may be a personal computer). SCI3 is used in
asynchronous mode (see figure 6.8). When the H8/3644F, H8/3643F, or H8/3642AF is set to boot
mode, after reset release a built-in boot program is activated, the low period of the data sent from
the host is first measured, and the bit rate register (BRR) value determined. The chip's on-chip
serial communication interface (SCI3) can then be used to download the user program from the
host machine. The downloaded user program is written into RAM.
After the program has been stored, execution branches to the start address (H'FBE0) of the on-chip
RAM, the program stored in RAM is executed, and flash memory programming/erasing can be
carried out. Figure 6.9 shows the boot mode execution procedure.
HOST
Rev. 6.00 Sep 12, 2006 page 120 of 526
REJ09B0326-0600
FV
PP
12 V *
Reception of programming data
Transmission of verify data
Figure 6.8 Boot Mode System Configuration
pin. Table 6.9 shows how to select
PP
on and off, see note 5 in section
PP
TEST
12 V *
V
SS
H8/3643F, or
H8/3642AF
RXD
TXD
Notes
H8/3644F,
SCI3