h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 582

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 19 ROM
Table 19.4 Boot Mode Operation
Table 19.5 System Clock Frequencies for which Automatic Adjustment of LSI Bit Rate is
Rev. 2.00 Dec. 05, 2005 Page 544 of 724
REJ09B0200-0200
Host Bit Rate
19,200 bps
9,600 bps
4,800 bps
Item
Boot mode
start
Bit rate
adjustment
Transfer of
programming
control
program
Flash memory
erase
Host Operation
Processing Contents
Transmits data H'55 when data H'00
is received error-free.
Transmits number of bytes (N) of
programming control program to be
transferred as 2-byte data (lower
byte following upper byte)
Continuously transmits data H'00 at
specified bit rate.
Receives data H'AA.
Transmits 1-byte of programming
control program (repeated for
N times)
Receives data H'AA.
Possible
Boot program
System Clock Frequency Range of this LSI
20 MHz
8 to 20 MHz
4 to 20 MHz
erase error
Communications Contents
H'00, H'00 ...... H'00
Upper byte and
lower byte
Echoback
Echoback
H'AA
H'XX
H'00
H'55
H'AA
H'FF
LSI Operation
Processing Contents
Branches to boot program at reset-start.
· Measures low-level period of receive data
· Calculates bit rate and sets it in BRR of
· Transmits data H'00 to host as adjustment
H'00.
SCI_1.
end indication.
Transmits data H'AA to host when data
Echobacks the 2-byte data received.
Echobacks received data to host and also
transfers it to RAM (repeated for N times)
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.)
Branches to programming control program
transferred to on-chip RAM and starts
execution.
H'55 is received.
Boot program initiation