HD6433044 Datasheet, PDF (591/867 Pages) Hitachi Semiconductor – Hitachi Single-Chip Microcomputer

18.6 On-Board Programming Modes
When an on-board programming mode is selected, the on-chip flash memory can be programmed,
erased, and verified. There are two on-board programming modes: boot mode, and user program
mode. These modes are selected by inputs at the mode pins (MD₂ to MD₀) and V_PP pin. Table 18-
12 indicates how to select the on-board programming modes. For information about turning V_PP on
and off, see note (4) in section 18.10, Flash Memory Programming and Erasing Precautions.
Table 18-12 On-Board Programming Mode Selection
Mode Selections
Boot mode Mode 5
Mode 6
Mode 7
User
program
mode
Mode 5
Mode 6
Mode 7
V_PP
12 V
MD₂
12 V
12 V
12 V
1
1
1
MD₁
0
1
1
0
1
1
MD₀
1
0
1
1
0
1
Notes
0: V_IL
1: V_IH
18.6.1 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 18-9). 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 18-10 shows the boot-mode execution procedure.
HOST
Receive data to be programmed
Transmit verification data
H8/3048F
RXD₁
SCI1
TXD₁
Figure 18-9 Boot-Mode System Configuration
582