Datasheet

Section 23 ROM
Rev. 3.00 Mar 21, 2006 page 620 of 788
REJ09B0300-0300
Table 23.5 Boot Mode Operation
Communications 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 start
Branches to programming control program
transferred to on-chip RAM and starts
execution.
H'00, H'00
. . .
H'00
H'00
H'55
Transmits data H'55 when data H'00
is received error-free.
Boot program
erase error
H'FF
H'AA
Receives data H'AA.
Receives data H'AA.
H'AA
Echobacks the 2-byte data received to host.
Echobacks received data to host and also
transfers it to RAM (repeated for N times).
High-order byte and
low-order byte
Echoback
Echoback
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).
Item
Boot mode start
• Measures low-level period of receive data H'00.
• Calculates bit rate and sets it in BRR of SCI_1.
• Transmits data H'00 to host as adjustment end
indication.
Bit rate adjustment
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.)
Flash memory erase
Transfer of programming control program
After receiving data H'55, transmits data
H'AA to host.