Datasheet
Section 7 ROM 
    Rev.5.00 Nov. 02, 2005 Page 97 of 500 
   REJ09B0027-0500 
Table 7.2  Boot Mode Operation 
Communication Contents
Processing Contents
Host Operation
LSI Operation
Processing Contents
Continuously transmits data H'00 
at specified bit rate.
Branches to boot program at reset-start.
Boot program initiation
H'00, H'00 
. . .
 H'00
H'00
H'55
Transmits data H'55 when data H'00 
is received error-free.
H'XX
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
H'AA reception
Upper bytes, lower bytes
Echoback
Echoback
H'AA
H'AA
Branches to programming control program 
transferred to on-chip RAM and starts 
execution.
Transmits data H'AA to host.
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'FF to host and aborts operation.)
H'FF
Boot program 
erase error
Item
Boot mode initiation
• Measures low-level period of receive data 
 H'00.
• Calculates bit rate and sets BRR in SCI3.
• Transmits data H'00 to host as adjustment 
 end indication. 
 H'55 reception.
Bit rate adjustment
Echobacks the 2-byte data 
received to host.
Echobacks received data to host and also 
transfers it to RAM. 
(repeated for N times)
Transfer of number of bytes of 
programming control program
Flash memory erase










