Boot Mode - Renesas F-ZTAT H8 Series Hardware Manual

Table 19.7 On-Board Programming Mode Selection
Mode Selections

Boot mode

Mode 5
Mode 6
Mode 7
User program Mode 5
mode
Mode 6
Mode 7
19.4.1 Boot Mode
To use boot mode, a user program for programming and erasing the flash memory must be
provided in advance on the host machine (which may be a personal computer). Serial
communication interface 1 (SCI1) is used in asynchronous mode (see figure 19.3). If the
H8/3048F is placed in boot mode, after it comes out of reset, a built-in boot program is activated.
This program starts by measuring the low period of data transmitted from the host and setting the
bit rate register (BRR) accordingly. The H8/3048F's built-in serial communication interface (SCI)
can then be used to download the user program from the host machine. The user program is stored
in on-chip RAM.
After the program has been stored, execution branches to address H'FF300 in modes 5 and 6 and
H'FFF300 in mode 7 in the on-chip RAM, and the program stored on RAM is executed to program
and erase the flash memory. Figure 19.4 shows the boot-mode execution procedure.
HOST
Section 19 Flash Memory (H8/3048F: Dual Power Supply (V
V
PP
12 V
Receive data to be programmed
Transmit verification data
Figure 19.3 Boot-Mode System Configuration
MD MD
2 1
12 V 0
12 V 1
12 V 1
1 0
1 1
1 1
Rev. 7.00 Sep 21, 2005 page 597 of 878
= 12 V))
PP
MD Notes
0
1 0: V
IL
0 1: V
IH
1
1
0
1
H8/3048F
RXD
1
SCI1
TXD
1
REJ09B0259-0700