Table 7.2 Boot Mode Operation - Renesas H8 Series Hardware Manual

Section 7 ROM
Table 7.2 Boot Mode Operation
Host Operation
Processing Contents
Continuously transmits data H'00
at specified bit rate.
Transmits data H'55 when data H'00
is received error-free.
H'AA reception
Transmits number of bytes (N) of
programming control program to be
transferred as 2-byte data
(low-order byte following high-order
byte)
Transmits 1-byte of programming
control program (repeated for N times)
H'AA reception
Rev. 3.00 Sep. 14, 2006 Page 104 of 408
REJ09B0105-0300
Communication Contents
H'00, H'00 . . . H'00
Boot program
erase error
Upper bytes, lower bytes
Branches to boot program at reset-start.
• Measures low-level period of receive data
H'00.
• Calculates bit rate and sets BRR in SCI3.
H'00
• Transmits data H'00 to host as adjustment
end indication.
H'55
H'55 reception.
H'FF
Checks flash memory data, erases all flash
memory blocks in case of written data
existing, and transmits data H'AA to host.
(If erase could not be done, transmits data
H'AA
H'FF to host and aborts operation.)
Echobacks the 2-byte data
Echoback
received to host.
Echobacks received data to host and also
H'XX
transfers it to RAM.
Echoback
(repeated for N times)
H'AA
Transmits data H'AA to host.
Branches to programming control program
transferred to on-chip RAM and starts
execution.
LSI Operation
Processing Contents
Boot program initiation