987
Chapter 53 Fixed Mode-Reset Vector / BOOT-ROM
2.Check for Boot Conditions
2.3 Internal Bootloader Description
If a valid boot condition for entering the internal bootloader was met, the ASCII-character “F” (0x46) will be
transmitted via UART0 (MB91V460) or UART4 (MB91460 series flash derivatives) to indicate that the bootloader is
ready to accept commands.
There are five different commands supported by the internal bootloader. See the table below for serial protocol of
these commands.
(Note) Software to transfer data using this protocol is available from Fujitsu.
Command PC to MCU MCU to PC Remark
READ
1 (0x01)
2 (0x02)
Address (4 bytes)
Size (2 bytes)
241 (0xF1)
130 (0x82)
Binary Dump
CheckSum (2 bytes)
Lo, MidLo, MidHi, Hi
Lo, Hi
Direct read and dump
Bootloader sends 16bit
checksum
WRITE
1 (0x01)
3 (0x03)
Address (4 bytes)
Size (2 bytes)
Binary Dump
241 (0xF1)
131 (0x83)
CheckSum (2 bytes)
Lo, MidLo, MidHi, Hi
Lo, Hi
Receive and store dump in
RAM
Bootloader sends 16bit
checksum
CALL
1 (0x01)
4 (0x04)
Address (4 bytes)
241 (0xF1)
132 (0x84)
Return Parameter
Lo, MidLo, MidHi, Hi
Calls specified Address and
waits for a return
The returned parameter in R4
will be echoed to the PC
CHECKSUM
1 (0x01)
5 (0x05)
241 (0xF1)
133 (0x85)
CheckSum (2 bytes)
MCU re-dumps 16bit
checksum (Lo, Hi) calculated
at last write or read operation
BAUDRATE
1 (0x01)
6 (0x06)
Baudrate (4 bytes)
241 (0xF1)
134 (0x86)
Lo, MidLo, MidHi, Hi
Initializes UART with new
baudrate value
